RFC 2822, 3.6.2 Error

Nextcloud version (eg, 12.0.2): 13.0.0
Operating system and version (eg, Ubuntu 17.04):
Apache or nginx version (eg, Apache 2.4.25):
PHP version (eg, 7.1):

The issue you are facing:

Error message after trying to share something even though it’s been successfully shared so it creates confusion

Is this the first time you’ve seen this error? (Y/N): Y

Steps to replicate it:

  1. Try to share any file
  2. Receive the error: Address in mailbox given [xxxx@] does not comply with RFC 2822, 3.6.2
  3. xxxx is the username

The output of your Nextcloud log in Admin > Logging:

There appears to be no error.

The output of your config.php file in /path/to/nextcloud (make sure you remove any identifiable information!):

PASTE HERE

The output of your Apache/nginx/system log in /var/log/____:

PASTE HERE

Without information of your setup and more error-messages, it’s difficult to say if there is a configuration error or a bug. To exclude a bug, you could try to use the same mail address and try to share something on the test setup: