Set up the Mail API

How do I set up the sending of SMS and RCS messages via the Mail API?

Contents of this help article:

Details on how to use the Mail API can be found here: Sending SMS via Email

Email to SMS allows you to send one or more SMS from your mail account via our gateway.

Email2RCS enables RCS messages to be sent via email.

The first setup

Log in to the webapp and navigate to the Mail API settings via the Developer menu item.


To be able to send SMS and other messages via mail, you need a sender address.
You can create this via the round green button with the plus on the bottom right.

A window opens where you can define a new sender address.

In the field Sender email address you enter the mail address from which you want to send the mail. It is also possible to specify all email addresses from a particular domain. To do this, enter the address in the format *, for example *
In the Key field, enter a password that makes sending messages via mail more secure. You can choose this key freely, but you may only use lower and upper case letters, numbers and the following special characters: - _ $ (hyphen, underscore and dollar sign).

In the Error mail address field you can specify a mail address to which you want to receive error messages. If you do not enter an address here, you will receive error messages at the sender address if you have activated error messages via mail in the additional settings.

Additional settings

You can click the settings button at the top right (blue cogs) for additional settings:


Maximum message length

Here you can specify a maximum number of characters after which the text of the mail is cut off and not sent. This is mainly to avoid unnecessary costs if signatures or similar attachments are sent by mistake.

To have better control over what you send, you can also enclose your content in double hashs: ##This is your text##
Everything outside these characters is not sent in the SMS.

Remove quotes 

Ensures that text passages that are placed in quotation marks are not sent in the SMS.

Notify on error

Here you can specify whether you want to receive error messages via email and HTTP request to your server.

Insert Email Sender in message

If you want, you can include your email address or part of it at the beginning of your SMS.

You can choose between three options:

Full address - inserts the entire address, e.g. "".

Local part of the address - e.g. "username" is inserted when sending from

No - does not send any parts of the address

If you want your SMS to be sent from a specific sender name, set a default sender name that can contain up to 11 alphanumeric characters. This name or this phone number will be used for all of your SMS if you do not specify another sender. Please note that replies are only possible to those SMS that have a number set as the sender name.

RCS messages always use the sender name you created when registering the agent.

Documentation of Mail API

Please find more details on email to SMS and email to RCS in our Mail API documentation.

If you have any questions, please feel free to contact our support.