Redmine

Could you try this patch?

diff --git a/app/models/mail_handler.rb b/app/models/mail_handler.rb
--- a/app/models/mail_handler.rb
+++ b/app/models/mail_handler.rb
@@ -177,7 +177,7 @@ class MailHandler < ActionMailer::Base
     end
   rescue ActiveRecord::RecordInvalid => e
     # TODO: send a email to the user
-    logger.error e.message if logger
+    logger.error "MailHandler: #{e.message}" if logger
     false
   rescue MissingInformation => e
     logger.error "MailHandler: missing information from #{user}: #{e.message}" if logger

When I saw your patch I was very optimistic that it would work, but so far I don't see any change. I applied it and confirmed that the change matches what you've shown above:

root@help:/opt/redmine# svn diff

Index: app/models/mail_handler.rb
===================================================================
--- app/models/mail_handler.rb  (revision 14618)
+++ app/models/mail_handler.rb  (working copy)
@@ -177,7 +177,7 @@
     end
   rescue ActiveRecord::RecordInvalid => e
     # TODO: send a email to the user
-    logger.error e.message if logger
+    logger.error "MailHandler: #{e.message}" if logger
     false
   rescue MissingInformation => e
     logger.error "MailHandler: missing information from #{user}: #{e.message}" if logger

and then I had the script scrape the 1MB email. I looked in the log and found that the line is still missing the prefix (line break between the two entries manually added):

root@help:/opt/redmine# grep -E 'unexpected error|can not be processed' log/development.log | cut -c 1-190

An unexpected error occurred when receiving email: Mysql2::Error: Data too long for column 'description' at row 1: INSERT INTO `issues` (`project_id`, `author_id`, `priority_id`, `tracker_id
Message 5696 can not be processed

An unexpected error occurred when receiving email: Mysql2::Error: Data too long for column 'description' at row 1: INSERT INTO `issues` (`project_id`, `author_id`, `priority_id`, `tracker_id
Message 5697 can not be processed

This is an SQL error, not a ActiveRecord::RecordInvalid error. That's why it doesn't fix your problem.
Could you try this:

### Eclipse Workspace Patch 1.0
#P trunk
Index: app/models/mail_handler.rb
===================================================================
--- app/models/mail_handler.rb    (revision 14858)
+++ app/models/mail_handler.rb    (working copy)
@@ -54,7 +54,7 @@
   def self.safe_receive(*args)
     receive(*args)
   rescue Exception => e
-    logger.error "An unexpected error occurred when receiving email: #{e.message}" if logger
+    logger.error "MailHandler: an unexpected error occurred when receiving email: #{e.message}" if logger
     return false
   end

We could use tagged logging for the mail handler to make sure that everything is prepended with something like [MailHandler]. But that would apply to all log messages, including template renderings and stuff like that, making it harder to catch usefull log messages:

Current log message:

  Rendered mailer/_issue.text.erb (7.0ms)
  Rendered mailer/issue_add.text.erb within layouts/mailer (13.0ms)
  Rendered mailer/_issue.html.erb (6.0ms)
  Rendered mailer/issue_add.html.erb within layouts/mailer (7.0ms)

Sent email "[OnlineStore - Bug #15] (Resolved) New ticket on a given project" (4ms)
  bcc: jsmith@somenet.foo
MailHandler: issue #15 created by John Smith

Received mail (635.0ms)

With tagged logging:

[MailHandler]   Rendered mailer/_issue.text.erb (7.0ms)
[MailHandler]   Rendered mailer/issue_add.text.erb within layouts/mailer (12.0ms)
[MailHandler]   Rendered mailer/_issue.html.erb (6.0ms)
[MailHandler]   Rendered mailer/issue_add.html.erb within layouts/mailer (7.0ms)
[MailHandler] 
Sent email "[OnlineStore - Bug #15] (Resolved) New ticket on a given project" (3ms)
  bcc: jsmith@somenet.foo
[MailHandler] issue #15 created by John Smith
[MailHandler] 
Received mail (628.0ms)

Jean-Philippe Lang wrote:

Both patches are committed in r14880.

Thanks!

I would still like to hear from you about the tagged logging solution.

If there is existing functionality (similar to syslog daemons) to filter on severity that could come in handy, otherwise I agree with your comment that tagging every line would make it more difficult to catch useful details.

I could see in a case where syslog functionality is available that MailHandler could be just one prefix used in the logging setup and that other "components" (for the lack of the correct word) would have their own prefix. Then if error messages were filtered to a separate file having the MailHandler prefix on all lines might prove useful.

Is there any existing functionality like that already in Redmine?

Jean-Philippe Lang wrote:

This is an SQL error, not a ActiveRecord::RecordInvalid error. That's why it doesn't fix your problem.
Could you try this:

[...]

It worked as you expected:

MailHandler: an unexpected error occurred when receiving email: Mysql2::Error: Data too long for column 'description' at row 1: INSERT INTO `issues` (`project_id`, `author_id`, `priority_id

Thanks.