Can I Use My Faculty etc. E-Mail-Address as Sender Address (Main E-Mail Address)?
E-mail addresses from other domains (eg. department, ZV, ...) can only be used as sender address (main e-mail address) and in your TUMonline businesscard, if this domain is managed by TUMonline. As long as this is not the case you can only use your @mytum.de- or @tum.de-addresses as sender address.
Please contact the IT administrator of your organisation/department.