We have several workflows that include email notification to our Outlook account. The notification has been working for a few months. Over the last few weeks one of our users has stopped receiving emails. We have verified the user email has not changed. We have created a new user and person with the email address and it still is not functioning. This issue is happening with both the prod and dev servers, and again only for one user. All other users are receiving emails. Any thoughts/areas I should check?
For investigation purposes, you could try non-workflow means to send email to user:
Subscribe (if subscription manager is On for your instance) the user to an object's event say: check-in/check-out or create or delete. Subscription should send out an email to the user. set valid email ID for 'infodba user' in TC organization. In case Teamcenter subscription email bounces back, infodba user will be notified.
 send email using tc_mail_smtp command line to the user. While you are at it verify using different SMTP servers
 Check if user's mail box is full or spam filter or outlook rules are filtering out Teamcenter mails. Sometimes, characterset encoding or originating SMTP server (bulk mailing server) translates as spam mail for outlook.
Can you share the workflow handler arguments used in this case? might help us narrow down on the potential areas to look for.