# Force use of email channel for outgoing mails
**URL:** https://community.zammad.org/t/force-use-of-email-channel-for-outgoing-mails/19800
**Category:** Technical assistance
**Created:** [March 12, 2026, 11:45am UTC](https://community.zammad.org/t/force-use-of-email-channel-for-outgoing-mails/19800 "2026-03-12T11:45:58Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@GarryG](https://community.zammad.org/u/GarryG)
#### Post date: [March 12, 2026, 11:45am UTC](https://community.zammad.org/t/force-use-of-email-channel-for-outgoing-mails/19800/1 "2026-03-12T11:45:59Z")
- Used Zammad version: 7.0.0
- Used Zammad installation type: package
- Operating system: Ubuntu 24.04
- Browser + version: not relevant
I’m having a problem with my Zammad setup and mail sending. When I originally installed the system, I only had IMAP based incoming mail. With that, everything worked fine, both incoming mails and outgoing notifications as well as mails written inside of Zammad.
As we use MS365 as mail service (not my choice), I configured MS Graph API for mail retrieval. I have a central shared mailbox which is correctly queried, and incoming mails are received and show up as ticket. Anyway, now neither notifications for new tickets, nor email replies work anymore, as Zammad tries to send those mails through MS365, instead of the configured SMTP server.
Everything I could find and try didn’t change the behavior. Is there any way to enforce using our SMTP server instead of the MS API?
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### Author:  [@MrGeneration](https://community.zammad.org/u/MrGeneration)
#### Post date: [March 19, 2026, 11:22pm UTC](https://community.zammad.org/t/force-use-of-email-channel-for-outgoing-mails/19800/2 "2026-03-19T23:22:11Z")
Zammad only supports SMTP or sendmail as notification channels.
Right now you cannot use Gmail or Microsoft 365 without workarounds…
There’s already a feature request for that, give it your heart on the first thread to vote.
> [@Email Notification channel must implement OAuth authentication](https://community.zammad.org/t/email-notification-channel-must-implement-oauth-authentication/9600):
>
> Hi, Since Microsoft and Google disable the basic authentication for SMTP, we cannot anymore use the Email channel to allow Zammad to send notification. It would be nice if we can have in the drop box “Mails send via” of the Notification by Email dialog box the ability to select account setup like Microsoft 365 or Google. Thanks for this awesome tool !
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### Author:  [@GarryG](https://community.zammad.org/u/GarryG)
#### Post date: [March 31, 2026, 9:56am UTC](https://community.zammad.org/t/force-use-of-email-channel-for-outgoing-mails/19800/3 "2026-03-31T09:56:30Z")
You don’t understand - I don’t WANT TO use MS365 for sending mail. I have an SMTP Server configured, but Zammad tries to send through MS365, resulting in this error:
MicrosoftGraphOutbound: Microsoft Graph API: The user account which was used to submit this request does not have the right to send mail on behalf of the specified sending account., Cannot submit message. (ErrorSendAsDenied) (no error code present) (MicrosoftGraph::ApiError)
Even removing the email address from the MS365 account in Zammad config doesn’t seem to help.
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### Author:  [@Raju001](https://community.zammad.org/u/Raju001)
#### Post date: [May 2, 2026, 8:15am UTC](https://community.zammad.org/t/force-use-of-email-channel-for-outgoing-mails/19800/4 "2026-05-02T08:15:35Z")
- Remove or disable the Microsoft 365 Graph email channel if you don’t want it used for sending.
- Reconfigure your setup using:
- IMAP (or Graph for inbound only)
- SMTP for outbound using your SMTP service provider (separate channel or proper configuration)- DigitalAka™ can be used as external server
- Ensure your **notification channel** is also set to SMTP (Channels → Email → Settings).