API Reference Guide

This is the documentation for ImprovMX HTTP REST API endpoints, which let you fully programmatically manage your domains and aliases for email forwarding.

Base URL

The base URL is: https://api.improvmx.com/v3

The v3 api was released on April 30th, 2020.

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

Error codes

Here are the main error codes you will encounter:

Code
Description
200
Success
The request was successful.
400
Bad Request
You passed an incorrect or missing parameter.
401
Authentication required
You tried to access an endpoint that requires authentication but you are not properly authenticated.
403
Forbidden
You don’t have permissions to access or edit this endpoint, e.g. a premium account is required.
500
Server 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
}

Domains

List domains

GET /domains

curl -X GET https://api.improvmx.com/v3/domains \
  -H "Authorization: Basic api:$API_KEY
Parameter
Type
Required?
Description
q
String
False
Search the domains starting from this value.
is_active
Boolean
False
Returns only active (1) or inactive (0) domains.
limit
Integer
False
Number of domains returned. Defaults to 50. Allowed values between 5 and 100.
page
Integer
False
Current page to load. 1-based (The first, default page is at page = 1).
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:

{
    "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
}

Add domain

POST /domains

curl -X POST https://api.improvmx.com/v3/domains \
  -H "Authorization: Basic api:$API_KEY" \
  -H 'Content-Type: application/json' \
  -d '{"domain": "piedpiper.com"}'
Parameter
Type
Required?
Description
domain
String
True
Name of the domain
notification_email
String
False
Email to send notifications to
whitelabel
String
False
Parent’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 domain details

GET /domains/:domain

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
}

Update domain

PUT /domains/: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"}'
Parameter
Type
Required?
Description
notification_email
String (email)
False
Email where notifications related to the domain will be sent
webhook
String (URL)
False
URL where email events related to this domain will be sent
whitelabel
String
False
The 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 domain

DELETE /domains/: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
}

Check MX of domain

GET /domains/:domain/check

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

List aliases

GET /domains/:domain/aliases

curl -X GET https://api.improvmx.com/v3/domains/piedpiper.com/aliases \
  -H "Authorization: Basic api:$API_KEY"
Parameter
Type
Required?
Description
q
String
False
Search (both alias and destination) starting by this value.
alias
String
False
Search only the alias value that starts with the given value.
page
Integer
False
Current 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
}

Add alias

POST /domains/:domain/aliases

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"}'
Parameter
Type
Required?
Description
alias
String
True
Alias to be used in front of your domain, like “contact”, “info”, etc.
forward
String (email)
True
Comma separated destination email(s) and/or webhooks to forward emails to.
{
    "alias": {
        "forward": "richard.hendricks@gmail.com", 
        "alias": "richard", 
        "id": 11
    }, 
    "success": true
}

Get alias details

GET /domains/:domain/aliases/:alias

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
}

Update alias

PUT /domains/:domain/aliases/: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"}'
Parameter
Type
Required?
Description
forward
String (email)
True
Comma separated destination email(s) and/or webhooks 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"}'
Parameter
Type
Required?
Description
alias
String
False
Alias to be used in front of your domain, like “contact”, “info”, etc.
forward
String (email)
False
Comma separated destination email(s) and/or webhooks to forward emails to.

Returns JSON like the following:

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

Delete alias

DELETE /domains/:domain/aliases/: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
}

Delete all aliases

DELETE /domains/:domain/aliases/aliases-all

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

Returns JSON like the following:

{
    "success": true
}

Bulk modify aliases

POST /domains/:domain/aliases/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"}'
Parameter
Type
Required?
Description
aliases
Array
True
An array containing a list of up to 500 objects with “alias” (your alias) and “forward” (the destination email)
behavior
String
False
Setting it to “add” (default) will cause the request to fail if the alias already exists. Setting it to “update” will update an existing alias. Setting it to “delete” will delete given aliases.

For add and update, 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
        }
    ]
}

For delete, returns JSON like the following:

{
  "deleted": [
    {
      "alias": "test", 
      "created": 1743462739000, 
      "forward": "myemail@gmail.com", 
      "id": 6
    }
  ], 
  "failed": [
    {
      "alias": "test1"
    }
  ], 
  "success": true
}

Logs

List domain logs

GET /domains/:domain/logs

curl -X GET https://api.improvmx.com/v3/domains/piedpiper.com/logs \
  -H "Authorization: Basic api:$API_KEY"
Parameter
Type
Required?
Description
next_cursor
String
False
Loads the logs after the given log.id. (Like 20201002014128.7ea8ee5b46)

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:

QUEUED
The email was accepted to be processed
REFUSED
The email was refused at the SMTP connection
DELIVERED
The email was successfully delivered to the end destination
SOFT-BOUNCE
The end destination temporarily refused the email. We will retry multiple times with increasing delay.
HARD-BOUNCE
The end destination rejected the email.

List alias logs

GET /domains/:domain/logs/:alias

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

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

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:

Parameter
Type
Required?
Description
next_cursor
String
False
Loads the logs after the given log.id. (Like 20201002014128.15a6659c5b46)

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.

List credentials

GET /domains/:domain/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
}

Add credential

POST /domains/:domain/credentials

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"}'
Parameter
Type
Required?
Description
username
True
String
Left part of the mailbox, like bighead for the email bighead@piedpiper.com
password
True
String
The 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.

Update credential

PUT /domains/:domain/credentials/:username

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 credential

DELETE /domains/:domain/credentials/:username

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
}