It appears that Apple is aware of this problem and is working on a fix for a future update. In the meantime you'll need to do the following to resolve the issue:
1. Quit Mail
2. Hold down OPT and select LIBRARY from the GO menu
3. Open Mail --> V2 --> MailData
4. First, DUPLICATE the "Accounts.plist" so you have a copy that says "Accounts Copy.plist" (Do not edit this one in the event you need to go back to it).
5. Open the original "Accounts.plist" with TextEdit
6. Scroll down until you see the following:
7. WITHOUT changing any other text, change the "25" to "587" so that it looks like this:
8. Close the Accounts.plist and relaunch Mail.
Now try sending an email.
Jose, is it a MobileMe email address you are using? The fix above should only work for MM accounts that are having trouble sending messages.
When you compose a message what smtp server are you using? Is it "MobileMe (MobileMe)"? Or some other smtp setting?
Go to Mail --> Preferences --> Accounts --> Outgoing Mail Server (SMTP) --> "Edit SMTP server list".
How many to do you have lsited there?
Well, I do have more than one account, one mobileme and two godaddy but if the fix its only for mobileme what I'm going to do with my godaddy accounts because these accounts I used for work and if I have to send a large file like I always do its going to take forever , and this is coming before lion but still no fix, I don't know why in my windows machine takes half a second to send an email from any account even with mobileme, anyway I hope apple will fix this some day
I will shortly describe my situation. have a MacbooAir 2011 i5 Lion. have a Gmail account configured in the Mail app. it took like forever sending a message, with or without attachment. now I've played with mail settings and the problem seems to be gone. I mean sending an email now takes up to 10 seconds and I really see the rpogress bar moving. so here is what I did (simple but might help):
Mail ==> Preferences ==> Composing ==> Send new messages from:
at default this setting is set to "Account of selected mailbox"
try and change that to the actual account address you're using.
underneath there is another setting which I've changed aswell - "Create notes in", also set it to your actual account
it seems to help to some extend but it true, the mail app is sooooooo slow and it takes waaaay to much of the resources (CPU).
Tried your solution but my port was already set to 587, when I see the activity window there is almost always an endeless Checking account connections and it says connecting to server smtp.me.com,
Mails do go out but painfully slow.
Did a clean install, that did not work, chatted with mobile three full days with no luck.
I have reported a bug
my isp is not blocking port 587, and it is a high bandwith connection, I can connect using the 587 port in terminal no problem
I have noted that when instead of using the wifi connection I use a personal HotSpot created by my iphone mail works fast and predictable, this is when instead of the arches in the toolbar there is a chain, so I assume the bug lies somewhere in the networking infrastructure of Lion.
There is another thread called "Mobileme SMTP timeout since Lion" you might read into the growing list of discontent in that thread.
Can you help?
Erich, here is what I would suggest trying. Repeat the steps outlined above once more. When you get to the line that contains "587", delete the numbers and reenter 587 again. Then save the file. Reboot, and see if things improve.
Again, perform this modification on the original file, not on the copy you made at the outset. The system will not use the copy at all. It's just there as a fallback position in the event the file you modify is corrupted. Cheers!