The log shows that all are being accepted, including <test1@cprk.com.my> and another invalid one on one of my domains, which end up in the bounce box. The other bad ones do not go to the bounce box, although there are a few from other mailings ending up there. The good addresses in the test (mine) are being delivered.
The errors are continuing to mount, but there are 40 lists on this installation, and I'm not sure which ones are producing the errors. The test list ( 6 addresses) does not seem to be.
Dailymail emails used to be delivered daily according to the cron setting, but that seems to have become erratic. The latest ones are Apr 24, 28, 30, May 3 - ie 2, 3 and 4-day intervals. Checking the cron settings - seems the hosting has changed on Direct Admin and there's a new cron setup - with no settings installed. I've added the LM cron, so will see what that produces tonight.