Problem with welcome email in multiserver setup (welcome mail not send because delay)

[radim_h]

Hello,

i have problem with welcome email in multiserver setup.

When account is created on master server, welcome email is sent. But slave mail server is creating mailbox bit later than it was added on master server (delay before cron on slave runs ang get changes from db)
Then email from master server is not delivered, getting message

Jul 12 11:12:48 web2 postfix/smtp[16948]: 2A389AC007A: to=<test@xxxxxx.cz>, relay=mail.xxxxxx.cz[109.123.xxx.x]:25, delay=0.27, delays=0.17/0/0.01/0.1, dsn=5.1.1, status=bounced (host mail.xxxxxx.cz[109.123.xxx.x] said: 550 5.1.1 <test@xxxxxx.cz>: Recipient address rejected: User unknown in virtual mailbox table (in reply to RCPT TO command))

Account on slave server is created correctly

How to fix this? it seems then needs to be some delay (2minutes) before welcome mail is sent ?