Hi Ben,
What happens when you try to resume? Do you get any error messages or unexpected output?
Have your emails gotten larger? If they are taking more time you could be reaching a server time limit on PHP scripts, although this is rare. Here's a test .php script you can upload and browse to:
<?phpset_time_limit(0);// length of test in seconds$s = 300;$start=time();echo "running...";while(true){ $elapsed = time()-$start; echo "elapsed = $elapsed"; if($elapsed % 5 == 0 ){ echo "$elapsed.. "; flush(); } if($elapsed > $s) break; sleep(1);}echo "<br>Looks good! The script ran for $total secs";?>
I should probably have a look at your queue, which I can do with access (http://listmailpro.com/support?t=other). Please include a note about the message subject(s) from Sent Messages of queues you could not resume, if they still exist.
Regards