postdrop: warning: mail_queue_enter: create file maildrop/44863.39055: Permission denied

I was having same with an install of Mac OS Server 5.2 Beta 4 when Xcode Server attempted to send post-integration email. I'm running this on El Capitan (10.11.6).

I have stopped the errors and allowed Xcode server to send emails as follows:

$ cd /Applications/Server.app/Contents/ServerRoot/usr/sbin
$ sudo ./postfix check
--------------------------------------------------------
        override:
config_directory: /Library/Server/Mail/Config/postfix
--------------------------------------------------------
postfix/postfix-script: warning: not owned by group _postdrop: /Applications/Server.app/Contents/ServerRoot/usr/sbin/postqueue
postfix/postfix-script: warning: not owned by group _postdrop: /Applications/Server.app/Contents/ServerRoot/usr/sbin/postdrop
postfix/postfix-script: warning: not set-gid or not owner+group+world executable: /Applications/Server.app/Contents/ServerRoot/usr/sbin/postqueue
postfix/postfix-script: warning: not set-gid or not owner+group+world executable: /Applications/Server.app/Contents/ServerRoot/usr/sbin/postdrop
$ sudo chgrp _postdrop postqueue postdrop
$ sudo chmod g+s postqueue postdrop
$ sudo ./postfix check
--------------------------------------------------------
        override:
config_directory: /Library/Server/Mail/Config/postfix
--------------------------------------------------------

So basically all I did was run a postfix check and fix the problems it listed. This does not mean I know what I am doing or that this is the correct solution. 😉

If there are any stray postdrop processes filling up your logs, they can be killed as follows. I suspect this means an email goes undelivered somewhere.

$ sudo killall postdrop

Regards,

Richard