Exchange Server 2016 and reconnected mailbox

[nodarmelitskauri]

Hello,

I have enabled user in active directory and reconnected disabled mailbox to this user. One of employees tried to send email to this user from outlook, to specify recipient he used outlook autofill and error message returned "The email address you entered couldn't be found. Please check the recipient's email address and try to resend the message. If the problem continues, please contact your email admin."

But if recipient is selected from address book, mail delivers normally, so what is the problem?

[#2]

@nodarmelitskauri 

Hello! You've posted your question in the Tech Community Discussion space, which is intended for discussion around the Tech Community website itself, not product questions. I'm moving your question to the Exchange space - please post Exchange questions here in the future. 

[#3]

LegacyExchageDN of previous account when mailbox was connected, will be still used when replied or used nick name cache... If you happen to find the legacy exchange dn then add that as X500 proxy address X500:<OldLegacyExchangeDN> of the current account...