Redmine

Also does not work if an email (with ticket header) sent by the system is replied to

We have similar problem with our Redmine, but I cannot confirm that it's the emoticon issue.
Sometimes once in a multiple emails, the message is marked as READ in inbox (Gmail IMAP) but is not updated in the Redmine.

What I've managed to find:

1. The problem is not present when creating new issue (ie. emails not connected to existing tickets are always read correctly into the system)

2. When someone "bumps" their email in existing issue bumped email is not read into the system (ie. sends an email to help@ inbox, issue is created, I answer in redmine, he/she gets notification and then answers this email notification once to update an issue, and then forwards own answer again to help@, then first mail is read correctly and second stays in the inbox - marked as READ but not put into redmine)

3. Yesterday we got an issue no #1213, my collegaue answered notfication about new issue creation, his message hasn't been put into Redmine, just marked as READ in gmail inbox - production.log stays silent about that, just some lines regarding "missing scope, creating scope :system" etc)

I conducted various test - I told him to answer again removing all other content of email, email signature, etc.
I moved issue to another project, I've even elevated his rights to Project Manager (who has all the privelages) - didn't help
I changed rake command in crontab (allow ovveride, no persmission check etc) didn't help
I tried to answer to issue myslef, forawrding his email - didn't help

It worked after I added myself as issue observer, answered issue in Redmine directly, and then went to my inbox and answered notification about that issue change

It's very weird because the problem happens to maybe 5% of mails (maybe even less) but sometimes it's a pain in the ***, especially when I cannot tell some people (from sales department) to "log in to redmine and answer there"...

Environment:
  Redmine version                4.0.6.stable
  Ruby version                   2.7.0-p0 (2019-12-25) [x86_64-linux-gnu]
  Rails version                  5.2.3
  Environment                    production
  Database adapter               Mysql2
  Mailer queue                   ActiveJob::QueueAdapters::AsyncAdapter
  Mailer delivery                smtp
SCM:
  Git                            2.25.1
  Filesystem                     
Redmine plugins:
  reopen_issues_by_mail          0.1.0

I made another Test:

1. First Mail - Standard with no smiley
2. Second Mail - Standard With a smiley between text
3. Third Mail - Standard with no smiley

1. Fist Mail - catch, Notfication Mail send, but not deleted!, marked in Mailbox as unread
2. Second Mail, no catch, no notification, no visible error msg, marked in Mailbox as read
3. Third Mail, no catch, no notification, no visible error msg, marked in Mailbox as unread.

After i delete the second mail, the catcher works again...

Environment:
  Redmine version                4.1.1.stable
  Ruby version                   2.4.10-p364 (2020-03-31) [x86_64-linux-gnu]
  Rails version                  5.2.4.2
  Environment                    production
  Database adapter               Mysql2
  Mailer queue                   ActiveJob::QueueAdapters::AsyncAdapter
  Mailer delivery                smtp
SCM:
  Subversion                     1.9.3
  Mercurial                      3.7.3
  Cvs                            1.12.13
  Bazaar                         2.7.0
  Git                            2.28.0
  Filesystem                     
Redmine plugins:
  additionals                    3.0.2-master
  mobile_issue_table             0.0.1
  redmine_checklists             3.1.18
  redmine_ckeditor               1.2.3
  redmine_contacts               4.3.2
  redmine_dmsf                   2.4.5
  redmine_issue_dynamic_edit     0.7.2
  redmine_issue_todo_lists       1.3
  redmine_issue_view_columns     1.0.1
  redmine_lightbox2              0.5.1
  redmine_logs                   0.2.0
  redmine_questions              1.0.2
  redmine_wktime                 4.1.1
  redmine_xapian                 2.0.3

Michael, for your problem, can you open a new tichet? it seems to be another issue on your case.

Great...i found my mistake.
Database was set to utf8mb4_unicode_ci but the config not ;)
Thank you very much for your support!