We developed a SMTP plugin that alternates with various SMTP servers: For example 4 SMTP servers, 1st mail is sent to SMTP-1, 2nd mail to SMTP-2, etc. After the 4th SMTP, we go back to the 1st, etc.
Using it with newsletter, it does not work, mails are always sent through the 1st SMTP server.
So my question: We tested it with a small qty of mails, 4!
How does Newsletter send mails? Does it send by batch of XX mails? In this case the 4 test mails would be sent together, to SMTP-1?
If so, can we assume that if we have bigger number of mails, let’s say 1000, 1st batch will be sent to SMTP-1, 2nd to SMTP-2 etc?
Hope you understand my question! THank you!