Better to fail loudly instead of silently breaking.

You're the hero!!!!

Thanks for the efforts. I will subscribe there to be up to date :-)

I use the Google Sync plugin to connect with our company Google Apps account. It also synchronizes the calendar entries as well as all other special stuff.
I'm quite sure that the standard POP/IMAP mechanisms in Outlook might not deliver the sender's address (however the receipient's address is contained in the logs above - my googlemail.com address).

Done. Now Outlook does not crash anymore, but GPGOL emits an error dialog:

Here you are