I mean I really, really like it a lot. I use it on my Windows XP machines; I use it on my Linux systems. I put it on my daughters Mac, and Ive replaced my wifes copy of Outlook Express on her Windows 2000 box.
They love it. I love it. But the love is not unconditional.
While I think Thunderbird is a great replacement for Outlook Express, Eudora or my own personal favorite for many years, Pegasus Mail, it just isnt quite ready for corporate, prime-time e-mail.
For starters, it still has some bugs in it.
Take, for example, the error message, "This folder is being processed. Please wait until processing is complete to get messages." Sometimes, this is a trivial error message, other times youll need to kill Thunderbird because that e-mail program is never coming back to life.
It depends entirely on whats causing the problem. There are, by my count, six ways to get this error message. And one of them leads to another, potentially more serious problem: anti-virus program incompatibility.
Thunderbird doesnt work and play well with all anti-virus programs. In particular, it can have serious trouble with Symantecs Norton Antivirus. Indeed, if you dont have the pair set up to play well together, you can actually lose messages.
This problem isnt unique to Thunderbird. Netscape, Mozilla and Outlook Express all share it. And there is a workaround, but still, it annoys me that Thunderbirds Windows installation program doesnt give you a heads-up that you may run into trouble if it detects this most popular of all anti-virus programs.
Ive also run into memory problems. To keep itself speedy, Thunderbird keeps messages from open folders in memory. Thats fine most of the time for most people, but as someone who gets thousands of messages a week, Ive run into situations where Thunderbird slowed to a crawl because I was running out of RAM.
A related problem is that you might think you could get rid of this problem by deleting messages, and you can. But you dont do it by deleting messages per se or even using the Empty Trash command.
No, all that does is hide messages. To really delete them, and gain back the wasted space, you need to compact your folders ... one by one.
This is documented, but when I delete something and then on top of that throw out the "trash," I assume that the message is gone. I think most users would, and since this can have an effect on performance, Id like to see the program default to combining delete and compact, or at least give me the option of running compact on all folders at a set time every day.