PROBLEM
I want to migrate my IMAP users to the atmail 7 cloud.

ENVIRONMENT

• atmail 7 cloud

CAUSE
Migration Requirement.

RESOLUTION

1. Install IMAPSYNC.
   You can either purchase the full source (http://imapsync.lamiral.info/), or grab earlier versions from Ubuntu/Debian repositories.
   
   
2. Once done, generate a list of your users in this format:
   [source-username],[password],[destination-username],[password]
   Separate new entries with newlines, like so:
   demo_zwi4@atmail.com,password,john@domain.com,password
demo_zwl0@atmail.com,password,jane@domain.com,password
demo_zzq6@atmail.com,password,june@domain.com,password
   
   
3. Save the file as migrate-users.csv.
   
   
4. Execute this command from the directory containing the CSV file:
   { while IFS=',' read u1 p1 u2 p2; do
imapsync --host1 [source-hostname] --authmech1 PLAIN --user1 "$u1" --password1 "$p1" --prefix1 INBOX/ --sep1 / \
--host2 [destination-hostname] --authmech2 PLAIN --user2 "$u2" --password2 "$p2" --prefix2 INBOX. --sep . ...
done ; }

 Executing the above command will then import all emails to the destination accounts.

Please note, this article presumes that the namespace separator of host1 is "/" and host2 is ".". 

--prefix1 INBOX/ --sep1 /

--prefix2 INBOX. --sep2 .

These are optional, but may be necessary as atmail strictly uses "." throughout its front end infrastructure.

NOTE: When migrating, the order of messages in the inbox will be arranged/displayed by the date the message was last modified (Not necessarily the date the email was received).