some email does not arrive
Thunderbird v51.0b2 Intermittent Sending to multiple users with email one message never arrives while all the rest are delivered. No message send failure, or returned undelivered message. Then if one of the other recipients forwards the same message to the failed user (copy and paste) then the message is delivered..
Opaite Mbohovái (2)
is it happening to particular domain or randomly happening??
note also 51.0b2 is well over a year old and no longer supported