While migrating from On-premises Exchange 2013 to O-365 through IMAP it is giving error after syncing approx. 200 mails "Delay response from source server".

Workaround :

1. Check IMAP endpoints and found ok.

2. If we did migration from individual mail user id password in a batch then its working perfectly. But while I did the migration from a common user ID and password then its giving error.

Waiting for reply....

Thanks & regards

• Moved by Jason Johnston [MSFT]Microsoft employee Tuesday, May 19, 2015 5:46 PM Not a development question.

Hi,

According to you post, I understand that run IMAP migrate with a common user ID and password failed and return error Delay response from source server, however it works fine when use individual mail user id password in a batch.
If I misunderstand your concern, please do not hesitate to let me know.

Here are the required attributes for each user:
1. EmailAddress specifies the user ID for the user's Exchange Online mailbox.
2. UserName specifies the logon name for the account to use to access the mailbox on the IMAP server.
3. Password specifies the password for the account in the UserName column.

If you want to use a common user ID and password (means super-user or administrator credentials), we need that super-user has the necessary rights to access all user mailboxes.
Heres an article about CSV files for IMAP migration batches, for your reference: https://technet.microsoft.com/en-us/library/jj200730(v=exchg.150).aspx
Besides, pay attention to below link about Migrate Email from an IMAP Server to Exchange Online Mailboxes:
https://technet.microsoft.com/en-us/library/jj874015%28v=exchg.150%29.aspx

Thanks