Got several mailboxes made in one batch. Identical, default configuration.

One of the users cannot send anything via SMTP - he gets 5.7.60 SMTP; Client does not have permissions to send as this sender.

This user has no problem sending same mails from OWA.

Also, adding an explicit Send As permission solves the problem with SMTP, but it's not required with other users - they send via SMTP without any problems.

What can be wrong?

(Exchange 2016)


Which client do you use to send message, Outlook or others? If using Outlook, which protocol do you use to configure the profile, Exchange/IMAP?

As OWA works, it may be related to client side. Compare the configuration with others to see if there is any difference, and try the account on other client machines to see if it could work.

  • The protocol, as evident, is the SMTP :) The client is Thunderbird. – Michał Sacharewicz Mar 6 at 10:17
  • Please check the SMTP server setting is correct under Outgoing Server (SMTP) tab in the account setting. For Thunderbird, you could try some Exchange add-in (e.g. ExQuilla for Microsoft Exchange). – Shaw Mar 7 at 9:18

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.