Unable to send mailing

ℹ️ Support
#1

When I put a campaign in queue, and process it, I see the message that the number of list members in that list have failed and will retry.

When I stop processing and look at the campaign in the campaign list, I see that it has an inflated number of number of messages sent. The number sent being over 10,000 more than the total list members.

The version I am using is 3.3.9 (unable to upgrade), and I am looking for advice on how to trouble shoot the issue.

#2

@Vanguard Look at the event log page for any errors that have been reported.

#3

The log of events shows that for each email in the mailing list it displays the following error:

Error sending email to [email-address-in-list] You must provide at least one recipient email address.

#4

@Vanguard I guess that there is something wrong with the email addresses that is making them be rejected.

#5

This is an established list that has been used for over a year. A mailing went out last week and in theory nothing has changed.