Custom SMTP with hosted Sharepoint and hosted Outlook

I was able to get helpdesk tickets to generate and notify agents using the baseline "[email protected]" email setting and a fwd’ing email address.

However, I would like to have the “from” address be from our own domain. So I tried to set up the “custom SMTP server settings” using and, along with a mailbox account.

I have been unable to get this to work and pressing the “test” button doesn’t appear to do anything or provide feedback.

If I leave the settings page and come back I see this error message:

Couldn’t connect to host A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond [::ffff:]:25

Please advise.


Hello @swilliams,

You have HelpDesk for Office 365, right?

Please, try using 587 port and no SSL:


You should see the “Email settings are valid” message after pressing the Test button. You should also receive a test email message into the mailbox your specified in the SMTP settings.

If you get different results please post here a screenshot of the error you get after pressing the Test button.

Anna Dorokhova
Plumsail Team