Email Forwarding API

This is the documentation for our API endpoints at improvmx.com. This lets you list, create, edit and remove domains and email aliases that you can forward to programmatically.

Base URL

The base URL of ImprovMX’s API is: https://api.improvmx.com/v3

The v3 api was released on April 30th, 2020. We suggest you update as soon as possible.

The v2 api has been marked as deprecated and was removed on June 1st 2024.

Authentication

First, retrieve your API Key from the API page of the ImprovMX app dashboard.

Authentication is done via basic access authentication.

Pass the string api as the username and your API key as the password, like in the following curl request:

export API_KEY={your_api_key}
curl https://api.improvmx.com/v3/domains \
  -H "Authorization: Basic api:$API_KEY"

That’s it, now you’re ready to communicate with our API.

Error codes

Here are the main error codes you will encounter:

CodeDescription
200Success
The request was successful.
400Bad Request
You passed an incorrect or missing parameter.
401Authentication required
You tried to access an endpoint that requires authentication but you are not properly authenticated.
403Forbidden
You don’t have permissions to access or edit this endpoint, e.g. a premium account is required.
500Server error
We ran into a bug… Reach out to us and we’ll fix it 🙂

When an error occurs, you will always receive a JSON response in the body explaining the reason for the failure. This should help you understand and fix your subsequent requests.

For instance, here’s an example of a Bad Request response returned by the server:

{
    "errors": {
        "email": [
            "You cannot use your domain in your email."
        ]
    },
    "success": false
}

Account

GET /account

Get details about your ImprovMX account

curl -X GET https://api.improvmx.com/v3/account \
  -H "Authorization: Basic api:$API_KEY"

Returns JSON like the following:

{
    "account": {
        "billing_email": null,
        "cancels_on": null,
        "card_brand": "Visa",
        "company_details": "1 Decentralized Street\n92024-
    2852 California",
        "company_name": "PiedPiper Inc.",
        "company_vat": null,
        "country": "US",
        "created": 1512139382000,
        "email": "richard.hendricks@gmail.com",
        "last4": "1234",
        "limits": {
            "aliases": 10000,
            "daily_quota": 100000,
            "daily_send": 200,
            "domains": 10000,
            "ratelimit": 10,
            "redirections": 50,
            "subdomains": 2,
            "api": 3,
            "credentials": 50,
            "destinations": 5
        },
        "lock_reason": null,
        "locked": null,
        "password": true,
        "plan": {
            "aliases_limit": 10000,
            "daily_quota": 100000,
            "display": "Business - $249",
            "domains_limit": 10000,
            "kind": "enterprise",
            "name": "enterprise249",
            "price": 249,
            "yearly": false
        },
        "premium": true,
        "privacy_level": 1,
        "renew_date": 15881622590000
    },
    "success": true
}

GET /account/whitelabels

Get whitelabeled domains

curl -X GET https://api.improvmx.com/v3/account/whitelabels \
  -H "Authorization: Basic api:$API_KEY"

Returns JSON like the following:

{
    "whitelabels": [
        {
            "name": "piedpiper.com"
        }
    ],
    "success": true
}

Domains

GET /domains

Retrieve a list of all your domains

curl -X GET https://api.improvmx.com/v3/domains \
  -H "Authorization: Basic api:$API_KEY"
ParameterTypeRequired?Description
qStringFalseSearch the domains starting from this value.
is_activeBooleanFalseReturns only active (1) or inactive (0) domains.
limitIntegerFalseNumber of domains returned. Defaults to 50. Allowed values between 5 and 100.
pageIntegerFalseCurrent page to load. 1-based (The first, default page is at page = 1).

Note: We limit to 200 aliases returned in each domain in this endpoint. If your domain has more, we recommend using the list aliases endpoint!

Returns JSON like the following:

{
    "domains": [
        {
            "active": true, 
            "domain": "google.com",
            "display": "google.com",
            "dkim_selector": "dkimprovmx",
            "notification_email": null,
            "webhook": null,
            "whitelabel": null,
            "added": 1559639697000,
            "aliases": [
                {
                    "created": 1702393755000, 
                    "forward": "sergey@gmail.com", 
                    "alias": "sergey", 
                    "id": 1
                },
                {
                    "created": 1702393755000, 
                    "forward": "larry@gmail.com", 
                    "alias": "larry", 
                    "id": 2
                }
            ]
        }, 
        {
            "active": false, 
            "domain": "piedpiper.com",
            "display": "piedpiper.com",
            "dkim_selector": "dkimprovmx",
            "notification_email": null,
            "whitelabel": null,
            "added": 1559639733000,
            "aliases": [
                {
                    "created": 1702393755000, 
                    "forward": "richard.hendricks@gmail.com", 
                    "alias": "richard", 
                    "id": 4
                },
                {
                    "created": 1702393755000, 
                    "forward": "jared.dunn@gmail.com", 
                    "alias": "jared", 
                    "id": 5
                }
            ]
        }
    ], 
    "total": 3,
    "limit": 50,
    "page": 1,
    "success": true
}

You can also use the q parameter to search for domains that start with the given value.

curl -X GET https://api.improvmx.com/v3/domains?q=pied \
  -H "Authorization: Basic api:$API_KEY"

Returns JSON like the following:

{
    "domains": [
        {
            "active": true, 
            "domain": "piedpiper.com", 
            "display": "piedpiper.com",
            "dkim_selector": "dkimprovmx",
            "notification_email": null,
            "webhook": null,
            "whitelabel": null,
            "added": 1559639727000, 
            "daily_quota": 500, 
            "aliases": [
                {
                    "created": 1702393755000, 
                    "forward": "richard@piedpiper.com", 
                    "alias": "*", 
                    "id": 3
                }
            ]
        }
    ], 
    "total": 1,
    "limit": 50,
    "page": 1,
    "success": true
}

POST /domains

Add a new domain

curl -X POST https://api.improvmx.com/v3/domains \
  -H "Authorization: Basic api:$API_KEY" \
  -H 'Content-Type: application/json' \
  -d '{"domain": "piedpiper.com"}'
ParameterTypeRequired?Description
domainStringTrueName of the domain
notification_emailStringFalseEmail to send notifications to
whitelabelStringFalseParent’s domain that will be displayed for the DNS settings.

Returns JSON like the following:

{
    "domain": {
        "active": false, 
        "domain": "piedpiper.com",
        "display": "piedpiper.com",
        "dkim_selector": "dkimprovmx",
        "notification_email": null,
        "whitelabel": null,
        "added": 1559652806000,
        "aliases": [
            {
                "forward": "contact@piedpiper.com", 
                "alias": "*", 
                "id": 12
            }
        ]
    }, 
    "success": true
}

GET /domains/:domain

Get domain details

curl -X GET https://api.improvmx.com/v3/domains/piedpiper.com \
  -H "Authorization: Basic api:$API_KEY"

Note: We limit this endpoint to 200 aliases per domain. If your domain has more aliases, we recommend the list aliases endpoint.

Returns JSON like the following:

{
    "domain": {
        "active": false, 
        "domain": "piedpiper.com", 
        "added": 1559639733000, 
        "display": "piedpiper.com",
        "dkim_selector": "dkimprovmx",
        "notification_email": null,
        "webhook": null,
        "whitelabel": null,
        "aliases": [
            {
                "created": 1702393755000,
                "forward": "richard.hendricks@gmail.com", 
                "alias": "richard", 
                "id": 4
            },
            {
                "created": 1702393755000,
                "forward": "jared.dunn@gmail.com", 
                "alias": "jared", 
                "id": 5
            }
        ]
    },
    "success": True
}

PUT /domains/:domain

Edit a domain.

NOTE: It’s not possible to change the domain name.

curl -X PUT https://api.improvmx.com/v3/domains/piedpiper.com \
  -H "Authorization: Basic api:$API_KEY" \
  -H 'Content-Type: application/json' \
  -d '{"notification_email": "email@example.com",
       "webhook": "https://requestbin.com/r/abc123",
       "whitelabel": "hooli.com"}'
ParameterTypeRequired?Description
notification_emailString (email)FalseEmail where notifications related to the domain will be sent
webhookString (URL)FalseURL where email events related to this domain will be sent
whitelabelStringFalseThe parent’s domain owner

Returns JSON like the following:

{
    "domain": {
        "active": false, 
        "domain": "piedpiper.com", 
        "added": 1559639733000, 
        "display": "piedpiper.com",
        "dkim_selector": "dkimprovmx",
        "notification_email": "email@example.com",
        "webhook": "https://requestbin.com/r/enbwnegkb25v",
        "whitelabel": "hooli.com",
        "aliases": [
            {
                "forward": "richard.hendricks@gmail.com", 
                "alias": "richard", 
                "id": 4
            },
            {
                "forward": "jared.dunn@gmail.com", 
                "alias": "jared", 
                "id": 5
            }
        ]
    },
    "success": True
}

DELETE /domains/:domain

Delete a domain

curl -X DELETE https://api.improvmx.com/v3/domains/piedpiper.com \
  -H "Authorization: Basic api:$API_KEY"

Returns JSON like the following:

{
    "success": true
}

GET /domains/:domain/check

Check if MX entries are valid for a domain

curl -X GET https://api.improvmx.com/v3/domains/piedpiper.com/check \
  -H "Authorization: Basic api:$API_KEY"

Returns JSON like the following:

{
  "records": {
    "provider": "cloudflare",
    "advanced": true,
    "dkim1": {
      "expected": "dkimprovmx1.improvmx.com.",
      "valid": true,
      "values": "dkimprovmx1.improvmx.com."
    },
    "dkim2": {
      "expected": "dkimprovmx2.improvmx.com.",
      "valid": true,
      "values": "dkimprovmx2.improvmx.com."
    },
    "dmarc": {
      "expected": "v=DMARC1; p=none;",
      "valid": false,
      "values": null
    },
    "error": null,
    "mx": {
      "expected": [
        "mx1.improvmx.com",
        "mx2.improvmx.com"
      ],
      "valid": true,
      "values": [
        "mx2.improvmx.com",
        "mx1.improvmx.com"
      ]
    },
    "spf": {
      "expected": "v=spf1 include:someservice.org include:spf.improvmx.com ~all",
      "valid": false,
      "values": "v=spf1 include:someservice.org ~all"
    },
    "valid": false
  },
  "success": true
}

The endpoint will return success: true when MX entries are well configured, success: false otherwise.

error may contain a reason why the entries are not valid.

Aliases

GET /domains/:domain/aliases

List a domain’s aliases

curl -X GET https://api.improvmx.com/v3/domains/piedpiper.com/aliases \
  -H "Authorization: Basic api:$API_KEY"
ParameterTypeRequired?Description
qStringFalseSearch (both alias and destination) starting by this value.
aliasStringFalseSearch only the alias value that starts with the given value.
is_activeBooleanFalseReturns only active (1) or inactive (0) domains.
pageIntegerFalseCurrent page to load. 1-based (The first, default page is at page = 1).

Returns JSON like the following:

{
    "aliases": [
        {
            "created": 1702982672000, 
            "forward": "richard.hendricks@gmail.com", 
            "alias": "richard", 
            "id": 4
        },
        {
            "created": 1702982672000, 
            "forward": "jared.dunn@gmail.com", 
            "alias": "jared", 
            "id": 5
        }
    ],
    "limit": 5,
    "page": 1,
    "total": 2,
    "success": true
}

POST /domains/:domain/aliases

Add new domain alias

curl -X POST https://api.improvmx.com/v3/domains/piedpiper.com/aliases \
  -H "Authorization: Basic api:$API_KEY" \
  -H 'Content-Type: application/json' \
  -d '{"alias": "richard",
       "forward": "richard.hendricks@gmail.com"}'
ParameterTypeRequired?Description
aliasStringTrueAlias to be used in front of your domain, like “contact”, “info”, etc.
forwardString (email)TrueDestination email to forward emails to
{
    "alias": {
        "forward": "richard.hendricks@gmail.com", 
        "alias": "richard", 
        "id": 11
    }, 
    "success": true
}

GET /domains/:domain/aliases/:alias

Get alias details

curl -X GET https://api.improvmx.com/v3/domains/piedpiper.com/aliases/richard \
  -H "Authorization: Basic api:$API_KEY"

Returns JSON like the following:

{
    "alias": {
        "created": 1702982672000,
        "forward": "richard.hendricks@protonmail.com", 
        "alias": "richard", 
        "id": 11
    }, 
    "success": true
}

PUT /domains/:domain/aliases/:alias

Update an alias

curl -X PUT https://api.improvmx.com/v3/domains/piedpiper.com/aliases/richard \
  -H "Authorization: Basic api:$API_KEY" \
  -H 'Content-Type: application/json' \
  -d '{"forward": "richard.hendricks@protonmail.com"}'
ParameterTypeRequired?Description
forwardString (email)TrueDestination email to forward emails to

Returns JSON like the following:

{
    "alias": {
        "forward": "richard.hendricks@protonmail.com", 
        "alias": "richard", 
        "id": 11
    }, 
    "success": true
}

You can also update an alias based on the “id” which is generated by our system when an alias is created

curl -X PUT https://api.improvmx.com/v3/domains/piedpiper.com/aliases/7 \
  -H "Authorization: Basic api:$API_KEY" \
  -H 'Content-Type: application/json' \
  -d '{"alias": "richard2",
       "forward": "richard.hendricks@protonmail.com"}'
ParameterTypeRequired?Description
aliasStringFalseAlias to be used in front of your domain, like “contact”, “info”, etc.
forwardString (email)FalseDestination email to forward emails to

Returns JSON like the following:

{
    "alias": {
        "forward": "richardhendricks@gmail.com", 
        "alias": "richardhendricks", 
        "id": 11
    }, 
    "success": true
}

DELETE /domains/:domain/aliases/:alias

Delete an alias

curl -X DELETE https://api.improvmx.com/v3/domains/piedpiper.com/aliases/nelson \
  -H "Authorization: Basic api:$API_KEY"

Returns JSON like the following:

{
    "success": true
}

POST /domains/:domain/aliases/bulk

Add aliases in bulk

curl -X POST https://api.improvmx.com/v3/domains/piedpiper.com/aliases/bulk \
  -H "Authorization: Basic api:$API_KEY" \
  -H 'Content-Type: application/json' \
  -d '{"aliases":[
         {"alias":"richard","forward":"richard.hendricks@gmail.com"},
         {"alias":"jared", "forward":"jared.dunn@gmail.com"}]
      "behavior": "update"}'
ParameterTypeRequired?Description
aliasesArrayTrueAn array containing a list of up to 500 objects with “alias” (your alias) and “forward” (the destination email)
behaviorStringFalseSetting it to “add” (default) will cause the request to fail if the alias already exists. Setting it to “update” will update an existing alias.

Returns JSON like the following:

{
    "added": [
        {
            "alias": "richard",
            "forward": "richard.hendricks@gmail.com",
            "id": 12345
        },
        {
            "alias": "jared",
            "forward": "jared.dunn@gmail.com",
            "id": 12346
        }
    ],
    "failed": [
        {
            "alias": "monica",
            "forward": "monica.hall@gmail.com",
            "id": 12347
        }
    ],
    "success": true,
    "updated": [
        {
            "alias": "dinesh",
            "forward": "dinesh.chugtai@gmail.com",
            "id": 12348
        },
        {
            "alias": "bertram",
            "forward": "bertram.gilfoyle@gmail.com",
            "id": 12349
        }
    ]
}

Logs

GET /domains/:domain/logs

Get domain logs

curl -X GET https://api.improvmx.com/v3/domains/piedpiper.com/logs \
  -H "Authorization: Basic api:$API_KEY"
ParameterTypeRequired?Description
next_cursorStringFalseLoads the logs after the given log.id. (Like 20201002014128.7ea8ee59fa894aa7a91415a6659c5b46)

Returns JSON like the following:

{
    "logs": [
        {
            "created": "2020-01-25 12:19:09+0000",
            "created_raw": "Sat, 25 Jan 2020 12:19:09 GMT",
            "events": [
                {
                    "code": 250,
                    "created": "2020-01-25 12:19:11+0000",
                    "id": "some_random_id",
                    "local": "mxb.infra.improvmx.com",
                    "message": "Queued",
                    "server": "mail-io1-f54.google.com",
                    "status": "QUEUED"
                },
                {
                    "code": 250,
                    "created": "2020-01-25 12:19:12+0000",
                    "id": "some_random_id",
                    "local": "gmail-smtp-in.l.google.com",
                    "message": "Sent.",
                    "server": "mail16.mxc.infra.improvmx.com",
                    "status": "DELIVERED"
                }
            ],
            "forward": {
                "email": "richard.hendricks@gmail.com",
                "name": "Richard Hendricks"
            },
            "hostname": "mail-io1-f54.google.com",
            "id": "20201002014128.5ea8ee59fa894aa7a9141e9665985b46",
            "messageId": "some_random_id",
            "recipient": {
                "email": "richard@piedpiper.com",
                "name": "Richard Hendricks"
            },
            "sender": {
                "email": "gavin@hooli.com",
                "name": "Gavin Belsonx"
            },
            "subject": "You are screwed, Piedpiper team!",
            "transport": "smtp"
        },
        {
            "created": "2020-01-25 12:18:46+0000",
            "created_raw": "Sat, 25 Jan 2020 12:18:46 GMT",
            "events": [
                {
                    "code": 250,
                    "created": "2020-01-25 12:18:47+0000",
                    "id": "another_random_id",
                    "local": "mxb.infra.improvmx.com",
                    "message": "Queued",
                    "server": "mail-pj1-f54.google.com",
                    "status": "QUEUED"
                },
                {
                    "code": 250,
                    "created": "2020-01-25 12:18:47+0000",
                    "id": "another_random_id",
                    "local": "gmail-smtp-in.l.google.com",
                    "message": "Sent.",
                    "server": "mail15.mxb.infra.improvmx.com",
                    "status": "DELIVERED"
                }
            ],
            "forward": {
                "email": "monica.hall@gmail.com",
                "name": "Monica Hall"
            },
            "hostname": "mail-pj1-f54.google.com",
            
            "messageId": "another_random_id",
            "recipient": {
                "email": "monica@piedpiper.com",
                "name": "Monica Hall"
            },
            "sender": {
                "email": "russ@threecommas.com",
                "name": "Russ Hanneman"
            },
            "subject": "Series A, bitches!",
            "transport": "smtp"
        },
        {
            "created": "2020-01-25 11:30:41+0000",
            "created_raw": "Sat, 25 Jan 2020 11:30:41 GMT",
            "events": [
                {
                    "code": 550,
                    "created": "2020-01-25 11:30:42+0000",
                    "id": "yet_another_random_id",
                    "local": "mxa.infra.improvmx.com",
                    "message": "5.7.1 Message considered as SPAM (Score of 5.8/5.0 with BAYES_20, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, FREEMAIL_FROM, HTML_MESSAGE, HTML_TAG_BALANCE_BODY, MIME_HEADER_CTYPE_ONLY, NO_RELAYS, URIBL_ABUSE_SURBL, URIBL_DBL_ABUSE_SPAM, URIBL_DBL_SPAM)",
                    "server": "mail-wm1-f67.google.com",
                    "status": "REFUSED"
                }
            ],
            "forward": null,
            "hostname": "mail-wm1-f67.google.com",
            "id": "20201002014128.7ea8ee59fa894aa7a91415a6659c5b46",
            "messageId": "yet_another_random_id",
            "recipient": {
                "email": "richard@piedpiper.com",
                "name": null
            },
            "sender": {
                "email": "spam@hooli.com",
                "name": "ThinkTeam"
            },
            "subject": "Enlarge your (pied)piper!",
            "transport": "smtp"
        }
    ], 
    "success": true
}

The logs array will contain all the processed emails. Each entry in the array will contain a list of events, related to all the actions taken by ImprovMX servers, which are:

QUEUEDThe email was accepted to be processed
REFUSEDThe email was refused at the SMTP connection
DELIVEREDThe email was successfully delivered to the end destination
SOFT-BOUNCEThe end destination temporarily refused the email. We will retry multiple times with increasing delay.
HARD-BOUNCEThe end destination rejected the email.

GET /domains/:domain/logs/:alias

Get logs for a domain’s alias.

This behaves similarly to the general logs endpoint, but only returns results for the requested alias.

curl -X GET https://api.improvmx.com/v3/domains/piedpiper.com/logs/richard \
  -H "Authorization: Basic api:$API_KEY"
ParameterTypeRequired?Description
next_cursorStringFalseLoads the logs after the given log.id. (Like 20201002014128.7ea8ee59fa894aa7a91415a6659c5b46)

NOTE: If you are requesting logs for a regex, you’ll need to URL-encode the characters, i.e. for (contact|support), you would make a request like domains/piedpiper.com/logs/%28contact%7Csupport%29.

Returns JSON like the following:

{
    "logs": [
        {
            "created": "2020-01-25 12:19:09+0000",
            "created_raw": "Sat, 25 Jan 2020 12:19:09 GMT",
            "events": [
                {
                    "code": 250,
                    "created": "2020-01-25 12:19:11+0000",
                    "id": "some_random_id",
                    "local": "mxb.infra.improvmx.com",
                    "message": "Queued",
                    "server": "mail-io1-f54.google.com",
                    "status": "QUEUED"
                },
                {
                    "code": 250,
                    "created": "2020-01-25 12:19:12+0000",
                    "id": "some_random_id",
                    "local": "gmail-smtp-in.l.google.com",
                    "message": "Sent.",
                    "server": "mail16.mxc.infra.improvmx.com",
                    "status": "DELIVERED"
                }
            ],
            "forward": {
                "email": "richard.hendricks@gmail.com",
                "name": "Richard Hendricks"
            },
            "hostname": "mail-io1-f54.google.com",
            "id": "20201002014128.5ea8ee59fa894aa7a9141e9665985b46",
            "messageId": "some_random_id",
            "recipient": {
                "email": "richard@piedpiper.com",
                "name": "Richard Hendricks"
            },
            "sender": {
                "email": "gavin@hooli.com",
                "name": "Gavin Belsonx"
            },
            "subject": "You are screwed, Piedpiper team!",
            "transport": "smtp"
        },
        {
            "created": "2020-01-25 11:30:41+0000",
            "created_raw": "Sat, 25 Jan 2020 11:30:41 GMT",
            "events": [
                {
                    "code": 550,
                    "created": "2020-01-25 11:30:42+0000",
                    "id": "yet_another_random_id",
                    "local": "mxa.infra.improvmx.com",
                    "message": "5.7.1 Message considered as SPAM (Score of 5.8/5.0 with BAYES_20, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, FREEMAIL_FROM, HTML_MESSAGE, HTML_TAG_BALANCE_BODY, MIME_HEADER_CTYPE_ONLY, NO_RELAYS, URIBL_ABUSE_SURBL, URIBL_DBL_ABUSE_SPAM, URIBL_DBL_SPAM)",
                    "server": "mail-wm1-f67.google.com",
                    "status": "REFUSED"
                }
            ],
            "forward": null,
            "id": "20201002014128.7ea8ee59fa894aa7a91415a6659c5b46",
            "hostname": "mail-wm1-f67.google.com",
            "messageId": "yet_another_random_id",
            "recipient": {
                "email": "richard@piedpiper.com",
                "name": null
            },
            "sender": {
                "email": "spam@hooli.com",
                "name": "ThinkTeam"
            },
            "subject": "Enlarge your (pied)piper!",
            "transport": "smtp"
        }
    ], 
    "success": true
}

SMTP Credentials

NOTE: SMTP is a premium feature.

GET /domains/:domain/credentials

Get domain’s SMTP credentials

curl -X GET https://api.improvmx.com/v3/domains/piedpiper.com/credentials \
  -H "Authorization: Basic api:$API_KEY"

Returns JSON like the following:

{
    "credentials": [
        {
            "created": 1581604970000,
            "usage": 0,
            "username": "richard"
        },
        {
            "created": 1581607028000,
            "usage": 0,
            "username": "monica"
        }
    ],
    "success": true
}

POST /domains/:domain/credentials

Add new SMTP credential

curl -X POST https://api.improvmx.com/v3/domains/piedpiper.com/credentials \
  -H "Authorization: Basic api:$API_KEY" \
  -H 'Content-Type: application/json' \
  -d '{"username": "bighead", "password": "abc123"}'
ParameterTypeRequired?Description
usernameTrueStringLeft part of the mailbox, like bighead for the email bighead@piedpiper.com
passwordTrueStringThe password for this account.

Returns JSON like the following:

{
    "credential": {
        "created": 1588236952000,
        "usage": 0,
        "username": "bighead"
    },
    "requires_new_mx_check": false,
    "success": true
}

The response field requires_new_mx_check will be True when creating your first SMTP credential.

NOTE: When setting up SMTP for the first time, we require two new DKIM CNAME entries and a new DMARC TXT entry in your DNS settings. Your domain will be unable to send SMTP until these are added.

PUT /domains/:domain/credentials/:username

Update SMTP credential

curl -X PUT https://api.improvmx.com/v3/domains/piedpiper.com/credentials/bighead \
  -H "Authorization: Basic api:$API_KEY" \
  -H 'Content-Type: application/json' \
  -d '{"password": "abcd1234"}'

Returns JSON like the following:

{
    "credential": {
        "created": 1588236952000,
        "usage": 0,
        "username": "bighead"
    },
    "success": true
}

DELETE /domains/:domain/credentials/:username

Delete SMTP credential

curl -X DELETE https://api.improvmx.com/v3/domains/piedpiper.com/credentials/russ \
  -H "Authorization: Basic api:$API_KEY"

Returns JSON like the following:

{
    "success": true
}