Exchange Email Server Interoperability Woes

Mine is a use case that is got to be exceedingly rare - maybe 0.001% of users or something like that. Still it's interesting to me, well, because it's my use case and perhaps it may have some general interest for users with less convoluted use case.

The setup - an corporate email Exchange server using IMAP.

A linux Thunderbird email client that is used as the email client of first resort. I also run Lightning on Thunderbird to get basic calendering functionality.

Occasionally use the Outlook Web client - whatever they are calling that these days.

Microsoft Outlook 2010 running inside of a virtual machine that can be accessed from linux. I use Outlook not as my primary email client but as a sort of secondary client because

• I can create Server based rules or filters to route certain emails to certain folders. Thunderbird filters are client based only.
• The Rules engine on Outlook seems more powerful to me over and above just the fact that the rules can be server based.
• Depending on how you actually set up Thunderbird's delete policy - if you set it up to move deleted messages to the Trash folder you actually have to go into Outlook to move those items to the real trash folder which is "Deleted Items" and then to go ahead and clean this folder. (This has always been true for me in the past - however - it may be that I just hadn't been "subscribed" to "deleted items" so maybe I was just making things hard for myself).
• Some of Outlook's find tools might be more powerful than Thunderbird's but I don't want to be too dogmatic here - maybe from time to time they just seem that way to me.
• Tighter integration in Outlook between email and meetings (Calender) but again this is changing somewhat as Lightning can mostly do most of what Outlook can do with meetings and calendering.
• Outlook can more easily tell you the mail quota and how much of it you've used. It also has superior mailbox cleanup tools.
• Also Outlook is the default client at work with Thunderbird (and Linux for that matter) being sort of "you're on your own".

So all of that being said it makes sense for me to have both clients going most of the time with the daily, repetitive process of reading, replying to, composing, deleting emails being done on Thunderbird but the less common "housekeeping" tasks such as setting up rules (filters), mailbox cleanup, scheduling meetings are often best done on Outlook.

For most people this is quite convoluted and for most of you maybe you don't need to read any farther. However, if this is you, or could be you, or you got here by accident and want to know how this is all going to turn out, then by all means read on!

I had it on my Todo list for a very long time to revisit all my folders and rules (filters) because of two main reasons.

1. Some of the filters were client based on Thunderbird and some were server based derived from Outlook so they were sort of a patchwork quilt.
2. And the main reason was that there was one folder that I know I had created on Outlook that Thunderbird could never see and messages were getting placed there (via an Outlook server side filter) and I was constantly missing them from Thunderbird.

The buildup for this conundrum is paragraphs and paragraphs of text. The solution turns out to be embarrassingly simple. Actually there are two solutions. On Thunderbird for the directories created on Outlook do

1. Menu | Edit | Account Settings | Server Settings | Advanced (tab) | Uncheck "show only subscribed folders".
2. While this should have been sufficient it didn't seem like it was in all cases so to handle these cases do Right Click on Inbox | Subscribe ... | Check the Outlook folders you wish to see.

So basically this was my problem all along. For most (sane) users who only use one email client the client they used to create a folder was also used to access that folder and if you create a folder with Thunderbird I assume that it automatically "subscribes" you to that same folder.

However if the folder was created by Outlook you either had to "subscribe" to that folder in Thunderbird or choose to "ignore" that attribute of the folders but until I figured that out I was running into seemingly anomalous situations.