How to prevent Outlook 2016/2019 IMAP sync issues

Outlook 2016/2019

Make sure to follow this guidance when creating folders in Outlook 2016/2019, otherwise it might lead to sync issues of your mailbox with the server.

Any of the following would indicate sync issues...

• Send/Receive process never ending
• New email not received promptly
• Email sent stuck in Outbox until Outlook is restarted
• etc...

Here is how to prevent them...

• Create folder as sub-folder of the Inbox folder (right click the Inbox folder then choose New Folder). You can create sub-folders in that folder afterwards. Just make sure the all folder tree is under Inbox.
• Remove any trailing space in folder name before creating it, for example don't create a folder "MyFolder " remove the trailing space so it become "MyFolder". The folder name shall never start with a space either...
  • Pay particularly attention to this when you copy/paste folder name from somewhere as it may be quite possible during selection or copy a trailing space may be added automatically, make sure to remove it after pasting prior creating the new folder.

• Avoid dual space in folder name. e.g "My Folder", remove the extra spaces so it would be "My Folder". Use only single spacing and never at the beginning or end of the folder name.

• Avoid special characters in folder names e.g:
  • Avoid Signs such as: * , & , etc...
  • Avoid Punctuation such as: ; (semi-colon) , : (colon) , . (dot) , .. (double dot) , ... (triple dot) , etc...
  • Avoid Brackets such as: ( , ) , [ , ] , etc...

• Privilege - (hyphen) or _ (underscore) as separator other than space if need be...

• Limit folder names to alpha and numeric characters where possible. For example don't create 'Folder 2018 & 2019', instead create 'Folder 2018_2019' or 'Folder 2018 2019' or 'Folder 2018and2019' for examples...

• When renaming a folder to change some letter case from "myFolder" to "MyFolder" (or any other possible option e.g "MYFOLDER",etc...), make sure to rename it first into an intermediary folder name with an extra character. For example rename "myFolder" into "MyFolder_" (adding underscore) and then again into "MyFolder" (removing underscore). That is because Outlook/Windows are case-insensitive while the email system is case-sensitive and Outlook does not cope correctly with it during folder rename... because he think "myFolder" and "MyFolder" are the same folder, consequently it does not command/instruct the server to modify folder name accordingly to case letter changes applied... creating a discrepancy that affect data sync... as the two folders (in Outlook and on server) become different... they don't sync any more with each other causing sync errors...

Outlook 2013 - IMAP implementation broken, not fit for purpose

IMAP implementation in Office 2013 is broken (don't send correct delete command to IMAP server) so don't use it at all, not fit for purpose!