Bounce emails problem

Good afternoon, for about a month and a half, every time I send a campaign, a high percentage of emails bounce. These emails have the following pattern in their content:

"This is an automatically generated Delivery Status Notification.

Unable to deliver message to the following recipients, due to being unable to connect successfully to the destination mail server."

At the end of the bounce email, an email address comes what makes each email different.

What is the reason a high percentage of emails are bouncing and all with the same pattern? Is it a matter of the SMTP server configuration that I am using or is it a phplist configuration where I have to make some adjustments?

You don’t mention what you have configured for the sending of your campaigns. Typically you would want to use a fixed ip address and a mail server that is properly configured. (host name, dns, dkim, spf, etc.).

If you have a phpList server on your local lan, the smtp sending should be configured to send through a properly configured email server that is on a public, static ip address.

Good morning, I have phpList installed on a local server where I work. phpList is configured with a mail server of the company with everything you mention (host name, dns, etc.); however, about a month ago this problem began to be presented and all bounced emails have the same pattern. Reading some discussion forums, they comment that it may be a problem of the mail server that does not have its DNS configured correctly, or that the DNS itself is not solving well and this is impacting the mail server and therefore its impacting phpList campaign emails. Will this be possible?

Is there any possible tha variable MAILQUEUE_THROTTLE with value 0 can cause these problem?

This could be an issue, in that most of the big email hosting companies (aol, gmail, hotmail, etc). want to see a nice, even flow of email from a givien IP address. If there is a big spike, then the receiving server will automatically limit the acceptance of the emails by applying a delay between the acceptance of one email and the next… you would get a ‘rate limited’ type of message in the sending server’s mail log.

Most users I run into want the maximum send rate, and then want inbox delivery. The ultimate goal is emails being opened… I’d suggest a slower sending rate, and sending constantly. You’ll get the most opens per campaign per hour doing it that way. The exact setting for Throttle would be based on looking at the sending server logs… but if you start at 250 emails/hr, and then raise slowly over time, that’s the best way. I have systems that send 20k emails/hr… but it’s been a process to get it to that speed.