The issue happens in Firefox, Safari, and Chrome for the Mac only. It has been reproduced in Mac OS 10.4, 10.5, 10.6 not Lion yet. SquirrelMail version is 1.4.22 running Mac OSX server 10.4.11 with updates to PHP version 5.2.4 OK. Cyrus IMAP4 v2.2.12-OS X 10.4.0 server.
This issue does not occur in SquirrelMail 1.4.21.
When a user composes a mail they click the send button. After that the mail is sent and the message does go to the sent mail folder. The only thing is that the right frame does not refresh to the inbox. It stays on the compose mail in the right frame and the user can click the send button many time and they do thinking the mail is not sent.
There is also I believe a related issue that has to do with the left bar not refreshing correctly. An example of this is when the "purge" link is pressed when mail is in the trash. One you click it it does work but does not refresh the bar and you can click it several time.
PC users appear unaffected at this point.
I see no server side errors but I see user side browser errors.
Failed to load resource: Operation could not be completed. (NSURLErrorDomain error -999.) :16080/webmail/src/right_main.php?mailbox=INBOX&sort=0&startMessage=1
Security Error: Content at http://xxx.mydomain.net:16080/webmail/src/right_main.php?mailbox=INBOX&sort=0&startMessage=1 may not load data from http://xxx.mydomain.net/webmail/src/webmail.php.
Unmatched </embed> encountered. Ignoring tag. left_main.php:73
I have since reverted to 1.4.21 and all seems well.