mbsync email suggestions

saebel

So I'm working on my plan for migrating the messages after using the WebFaction -> Opalstack migrator to transfer over all the mail boxes and email addresses.
I'm pulling my thoughts and instructions from the following pages:
https://help.opalstack.com/article/107/importing-email-from-another-provider
https://isync.sourceforge.io/mbsync.html

I've already used mbsync to transfer over one of my websites. But that was a very simple one with very little content/message count. The next phase is going to be multiple mailboxes with thousands and thousands of messages.

I was wondering whether it's more efficient to either:
a. Do it all at once after the DNS entries are pointing to the new server or
b. if it's better to do it in two passes:
1. once before the DNS switch so that the box is there and ready to receive emails and then
2. once after the DNS switch to sync any emails that may have come in after the DNS switch.

Basically, what I want to know is that if I do it in two passes, will the second pass be much short since it's just adding new stuff/changes? Or it will it take as long (or even longer) because it has to compare all the messages between the two accounts/mailboxes?

Also, I think I can use just one mbsync file to run all the mailbox conversions at once, as long as I have each account, store, and channel accounted for. Here's a sample code of what I have in mind which would (in theory) pull two mailboxes in one shot.

Create Slave
Sync Pull
CopyArrivalDate yes

IMAPAccount wf_1
SSLType IMAPS
Host mail.webfaction.com
# change the following two lines to match old account settings
User webfaction_mailbox_1
Pass webfaction_mailbox_1_password

IMAPStore wf_1
Account wf_1

IMAPAccount opal_1
SSLType IMAPS
Host mail.us.opalstack.com
# change the following two lines to your Opalstack account settings
User opalstack_mailbox_1
Pass opalstack_mailbox_1_password

IMAPStore opal_1
Account opal_1

Channel main_1
Master : wf_1:
Slave : opal_1:
Patterns *

IMAPAccount wf_2
SSLType IMAPS
Host mail.webfaction.com
# change the following two lines to match old account settings
User webfaction_mailbox_2
Pass webfaction_mailbox_2_password

IMAPStore wf_2
Account wf_2

IMAPAccount opal_2
SSLType IMAPS
Host mail.us.opalstack.com
# change the following two lines to your Opalstack account settings
User opalstack_mailbox_2
Pass opalstack_mailbox_2_password

IMAPStore opal_2
Account opal_2

Channel main_2
Master : wf_2:
Slave : opal_2:
Patterns *

Feedback, real world experience before I pull the trigger would be welcome.

saebel

Okay, so I tried my thing. It sorta worked. It took multiple passes because sometimes it would timeout.

One thing that concerned me was that it appeared none of the subfolders had migrated. I'm using Outlook. When I created the new accounts, it only set the top tier inbox to "subscribed", so all the subfolders were hidden. Not sure what the solution is for other apps, but for Outlook:

Right click on the Inbox
Select "IMAP" folders.
Uncheck the box that says "When displaying hierarchy in Outlook, show only subscribed folders.
Click Apply, then OK.

The other option is download all the folders and subscribe to them all (I think?), but I didn't bother because the above worked for me.

sean

saebel Cool that this (mostly) worked for you! 🙂

Did you have any problems with memory usage or duplicate messages when running multiple passes?

What was the exact command you used for each pass?

saebel

sean
As far as I could tell, I did not get any duplicates.

I ran the exact same command each time. I think what happened is that it just got "lost" and "disconnected". When I reran it, it seemed to pick up where it left off? It's hard to tell because I have multiple mailboxes and thousands of messages. I don't know if I would notice if anything was missing. I did not see any duplicates.