This past weekend saw a large number of spammer/bot accounts being created.  Indeed, they have been banned given the high record of spam activity, trusted reporting sites such as StopForumSpam and the like noting their credentials.  It is sad that most of the accounts are using a service prior unseen here that was, until recently, considered safe.
 
Created in 1999 by Cyber Folks S.a, the Op.Pl service is an eMail service out of Poland, and its domain regularly renewed through RingPublishing. It was considered a viable and safe service.  But it has not remained thus.  And there has been little, if any, information since about the business.
 
When bots began appearing last week, the online service known as Scam Detector gave op.pl an 85% assurance of safety.  However, that has 'quickly and sharply' fallen to just 64.2% as of today's date.  And  AlienVault® (Open Threat Exchange®) now has op.pl on its list as having become a likely hub/source for spam content.  As of now, there is no information about the website other than its domain registration and renewal dates.
 
Since typing this notification, another bot had attempted to create an account with op.pl.  Upon seeing this, went to our "Who's Online" page to see the IP address (an Admin perk) of the guest attempting to Register, and saw it as another intrusive spambot/spam account.  Ergo, the ban of op.pl is 'effectively' in place.
 
So until as such time that op.pl addresses this issue with their service, the eMail service will not be accepted.

Apologies