In 1.8.5, the mailin feature doesn't work properly. It may work for some combination of mail systems, but not for others. And it does not properly handle multiple mailed-in messages when a page load is attempted.
Specifically, some combination of mail client and mail server caused the email address extraction to leave a newline on the end, which should be trimmed.
Also, in determining the type of message, a case-sensitive string comparison is done against "text/html", which won't match for upper or mixed-case.
Finally, there's a bug (probably a minor design flaw) in the way the histlib object is created in lib/tikilib.php, such that if the code is executed twice in the same session, it will fail the second time because the $histlib object isn't created.
Last but not least, after parsing the message, if there are no parts found, the loop that attempts to process them assumes that $output->parts exists, which it may not.
strip() the email address to remove the new line.
strtolower() the message type ('text/html') before doing the comparison.
Manually create the $histlib object if it does not exist after 'include_once'.
Check to see if $output->parts exists before using it.
For patch, see attachments to this bug report.
To help developers solve the bug, we kindly request that you demonstrate your bug on a show2.tiki.org instance. To start, simply select a version and click on "Create show2.tiki.org instance". Once the instance is ready (in a minute or two), as indicated in the status window below, you can then access that instance, login (the initial admin username/password is "admin") and configure the Tiki to demonstrate your bug. Priority will be given to bugs that have been demonstrated on show2.tiki.org.
To help developers solve the bug, we kindly request that you demonstrate your bug on a show.tikiwiki.org instance. To start, simply select a version and click on "Create show.tikiwiki.org instance". Once the instance is ready (in a minute or two), as indicated in the status window below, you can then access that instance, login (the initial admin username/password is "admin") and configure the Tiki to demonstrate your bug. Priority will be given to bugs that have been demonstrated on show.tikiwiki.org.