in OWA, client cannot open some emails. HTTP404 error

[Benjaminle]

When my clients logged on to OWA, he cannot open some of his emails in the Inbox. Everytime he clicks on them, he received the Page cannot be found, HTTP 404 error. Some of these emails have attachments and some don't.

 

[g3ck0]

Are there any punctuation marks in the subject line, especially at the end. I had this problem before and narrowed it down to OWA not being able to handle some punctuation marks.

 

[Benjaminle]

I found the resolution for this. OWA will have this error if you have URLScan installed. Uninstall URLScan and remove your server will resolve your issue. URLScan defaults configuration will not allow you to open mails with "..","&", etc. sign on subject. You can also modify the urlscan.ini file as well.

 

[Niksen]

You should't uninstall urlscan, just search and find urlscan.ini and change the proper value. urlscan is a must on a OWA

 

[Benjaminle]

I modified the urlscan.ini file on both my front-end and back-end servers. I restarted IIS as well but it didn't work. I didn't try restarting the servers yet. I know for sure that if I uninstall URLScan, then it would work because I never had these issues before URLScan was installed. MS Knowledge Page -KB320089- said all you need to do is remove lines under the [DenyURLSequences] section in the ini file. Didn't say anything about restarting servers or services.