I know the issue of canonical addresses has been discussed, but this is unusual and I couldn't find another reference. We have our server set up on FDQN zimbra.domain.com and we want mail to be sent "from" domain.com so for each user we have the canonical address domain.com.

The issue we have is that this works well for all users but one. We have one user for whom the canonical address is ignored. We have removed and added the canonical name, tried different canonical names all to no effect.

We are at a loss. Does anyone have any ideas?

Thank you.