Recipient address rejected

[etienne7702]

Hi

I have domain1.com and domain2.com both hosted on my server.

domain1.com host mail and website
domain2.com host website only. mail hosted on office365.

when email from domain1.com to domain2.com i get error.

Your message did not reach some or all of the intended recipients.
     Subject:  test
     Sent:     14-03-2018 04:44 PM
The following recipient(s) cannot be reached:
     user on 14-03-2018 04:44 PM
           Server error: '450 4.1.1 <user@domain2.com>: Recipient address rejected: User unknown in virtual mailbox table'
thanks

[TGates]

Does the account 'user@domain2.com' exist? Can you send mail from user@domain2.com?

[etienne7702]

Hi

It does exist on
All of ....@domain2.com emails are on Office365 account

[TGates]

What does the email error log show?

[davidlambda]

Hi

It does exist on
All of ....@domain2.com emails are on Office365 account

Is there any solution?

I have the same problem...