Sending mails slow down

IT helpdesk

New Member
I tried to send emails to around 10,000 recipients. It looks pretty fast from the very beginning (can see the count on the console keep going up quickly), but it ended up takes over 10 hours to finish sending out all 10,000 emails. We have the settings grouping 500 recipients at an interval of 5min, i.e. sending to 6000 recipients per hour.
I have no idea why it is so slow. Here is the log.

MaxBulk Mailer Delivery Report [#13] - 10-11-2018
Mailer version: 8.6.6-US Pro - Registered
Machine OS/speed: Windows 10 (Build 14393)/3.067Ghz
Streams: 5 [5 Used | 48 Dropped] Single Server
Delivery mode: Singly (Tag processing ON)
SMTP server address: [Port: Default] SSL Off
Authentication: None | []
Groups: 500 [Interval: 00:05:00]
Delivery start date: 09-11-2018 at PM 03:58:13
End date: 10-11-2018 at AM 02:46:28
Total duration: 10 hour(s), 48 minute(s), 14 second(s) - Retries: 14/10
Rate: 0.26 recipient(s)/second
to a total of: 9,997 recipient(s) [9,997/9,997]
List name: unknown
Sent: 9,947
Failed: 50 undelivered [Connection dropped by server]
Errors: 50
Mail subject: xxxxxxxxxxxxxxxxxxxxxxx
Mail priority: Normal
Reply To: xxxxxxxxxxxxxxxx (Sender)
Errors: xxxxxxxxxxxxxxxx
Return receipt: No
Mail format: Styled Text | utf-8 | quoted-printable
Mail size: 1.50 KB (Doesn't include attachments)
Attachments: 1 (3.8 KB)
Encoding: Base64
MLM: Click-through tracking [Deactivated]


Did You check your ESP if this amount of mail is within their daily limits? To preventie spam Some ESP have a limit.


New Member
I think that the email limit has ended, try to increase it. I had a similar situation when I sent an SMS through BSG, my limits for sending is off and the messages stopped sending. When I increased the limit all messages went fine!