I recently installed zcs 802 NE (starter ed) to replace a ZCS 609 FOSS
Everything has worked fine for about two weeks

Today I remembered I forgot to activate the system pop downloader using zmfetch
the zmfetch script works if entered manually

As zimbra I added the script call to crontab using crontab -e

As it didn't seemed to have an effect, I restarted the zimbra - zmcontrol stop followed by zmcontrol start

all the services stopped and started as usual.

but now I cannot send a message anymore. Everytime the error below appears.
I since then restarted the server, the client, removed the crontab line, restarted again, but to no avail

the admin page does not show any issues, teh zcs client loads as usual

Where can I find what is wrong?

An unknown error (mail.TRY_AGAIN) has occurred.
method:	[unknown]
msg:	try again: Unable to connect to the MTA
code:	mail.TRY_AGAIN
detail:	soap:Receiver
trace:	qtp1635701107-544:

Body: {
  SendMsgRequest: {
    _jsns: "urn:zimbraMail",
    m: {
      e: [
        // [0]: