Not able to receive invitation mail

[Jens Roggeband]

I have invited a team member to join JIRA, but the invitation mail is never received, resending and recreating the user does not help.

Using a different mail address does work, but this is a private mail address and is not desirable.

Adding other team members with the same mail server does work however. 

Also, this user will get notifications for tickets he is assigned to, but he cannot log in, in any way.

What can we do to solve this? We use JIRA cloud.

[Paulo Hennig]

Hey, Jens.
It's odd that this behavior is happening to a single user. I understand that this isn't happening to other users with the same mail server, but I'd recommend you to double check this mail server's logs in order to see if this email is indeed hitting your mail server. Otherwise, we'll have to identify if the issue is not on the Jira side in order to apply a fix accordingly.

However and since this user is getting other notifications, may I know what's the results when clicking on "forgotten password" (Customer Portal)? I'm asking for this so he can try to change his password and then, authenticate correctly.