Outlook automatically adds the local domain name to sent emails

[Martrim]

Let's say for the rest of this question that our domain is cityname.be



We occassionally have the issue that when one of our users sends a mail to an external address (let's say: address.test@hotmail.com) Outlook adds our domainname to it so it thinks the mails wants to go to address@hotmail.com@cityname.be .

This results in an error like this:


IMCEAINVALID-address+2Etest+40hotmail+2ECom@Cityname.be
Remote Server returned '550 5.1.15 RESOLVER.ADR.InvalidInSmtp; encapsulated INVALID address inside an SMTP address (IMCEAINVALID-)'


How does this happen?

Continue reading...