[Dovecot] multiple domains for the same user

I have postfix and dovecot set up to use virtual domains. I am now experiencing a problem that when I log in as user1@domain1.tld and then log in as user1@domain2.tld all the emails are downloaded for user1@domain2.tld as it thinks all the messages are new.

is there anyway to stop dovecot from saying that all the messages are new?