When sending your campaigns, you may find that an additional header is added to the top of your outgoing messages. In Microsoft Outlook, the "From" area will show the name of your account with us, the domain name of the mail server that sent the message, the words "sent on behalf of," and your specific "From" email address.
In Gmail, there is a similar message, although the wording is slightly different.
Why does this header exist?
We allow all of our clients to enter any email address they like as the "From" sender address for each campaign. However, this also means that the emails you send using our platform will be sent from a different domain (one of our mail servers) than the domain listed in your custom "From" email address.
Although the From address is set to anything you choose, for example, "email@example.com," the email message originates from a mail server with a domain name of something like "acems1.com."
Outlook and Gmail display a header message to inform recipients the email is from a "From" address that differs from the address of the actual mail server because this can sometimes indicate a message has been "spoofed" or "faked."
Since we've properly authenticated your emails, there's no need to worry about this negatively affecting your messages. This header doesn't "hurt" or "help" your deliverability; it's just an informative message to recipients at Outlook and Gmail.
Many users prefer to remove the "Sent on behalf of" header because it looks messy or may be confusing. It's straightforward to remove this header, and there are no negative consequences of doing so.
How do I remove the header?
Once you complete the setup outlined below, note that it can take a few hours before the "sent on behalf of text" is removed. If it doesn't appear to be working at first, wait a few hours and retry.
The "sent on behalf of" text in your message header can be removed by setting up DKIM for your sending domain. After completing this process, the heading of your messages appears a little cleaner, and with your own "From" email address displayed (the name of our mail server will not be displayed).
To set up DKIM, log in as your account's admin user, then click "Settings" located on the left-side menu.
Next, click the "Advanced" tab located on the left side of your screen. Click "I will manage my own email authentication" option.
While there are several options on this page, you only need to set up DKIM to remove "sent on behalf of."
Enter your domain name in the corresponding DKIM field and click "Generate":
This will generate records that you can then add to your DNS as TXT records at your registrar or hosting provider (e.g. Godaddy).
Click "Save Settings" on the top right of your screen when finished.
Once complete, the "sent on behalf of" text will be removed from all outgoing emails sent using the domain you set up.
As a reminder, it can take a few hours for the DNS records to propagate. If it doesn't appear to be working at first, wait a few hours and retry.
For more information about DKIM and email authentication, you can read here.