Error sending mail with eNewsletter

I am attempting to send a message today to about 1600 recipients. I got about 400 sent, and then suddenly I started getting an error that there was a problem sending and to check my settings. My smtp settings are correct, and a test of the settings (3 times now) always goes through properly.

Any ideas on how to troubleshoot this? I do not see any errors in my logs. It doesn't seem likely (although possible I guess) that any of the ISPs involved in this transaction are blocking traffic, because the tests work.

Thanks!

Danita

  • WebDoc

    Hello Danita,

    I don't know if I can be of much help here but I will give it a shot.

    Sometimes hosts will limit how many emails you can be sent in a certain period of time. There are a couple resons for this that I can think of at the moment, 1.) spamming controls and 2.) server CPU usage. Where is your email account hosted (Gmail, Outlook.com, Yahoo, etc.)? Maybe try contacting your host to see if there is a limit. If so, you could possibly break your list into segmented groups and schedule at intervals within your host's limits. I know that would be a pain, especially as your list grows... That is my two cents. Hope it helps.

    All the best,
    David

  • Vaughan

    Hi Danita,

    Hope you're well?

    Further to the excellent information from @webdoc above, which is certainly a possibility you will need to check with your host.

    Could you tell me which method of sending are you using, PHPmail or SMTP?

    Much of the time, by using SMTP you can get by these restrictions from hosts.

    An alternative would also be to use mandrill. https://wordpress.org/plugins/wpmandrill/

    Hope this helps

  • Danita

    A bit more info:

    1. I host my own mail server on SLES 12. It listens on port 26, and uses TLS for authentication. If I go into eNewletter, Settings, Outgoing Mail Settings (screenshot attached), I can send a test message, which sends successfully, and is delivered to my mailbox.
    2. WordPress is self-hosted on Centos at Digital Ocean. I can ssh into this server and telnet to the mail server on port 26 and manually send a message with no problem.
    3. If I go to my newsletters, edit the newsletter and choose "Send Preview", the message sends without problem.
    4. When I attempt to "continue" my sending, which stopped after about 414 messages being sent, I get an error as in error-sending.png

    So, it's pretty clear that the smtp settings are correct, as both a server settings test and a newsletter preview send without problems. But for some reason this specific newsletter will not complete its sending. I do not even see an attempt on my mail server. It would be helpful if there was a log that would show me what is happening. /var/log/messages shows no errors on the WordPress server. The /var/log/maillog on the wordpress server also shows nothing. I think my next step is to look in the mysql database, try to find the next "attempted" recipient and change the status to sent to see if there is something specifically wrong with the record or something.

    Thanks.

    Danita

  • Danita

    By the way, I use eNewsletter frequently. I have one list that is about 5000 recipients. I actually sent to the same group as this 1600 recipient message on Friday. Today's message was just a followup to that one. So this is a new occurrence, and as I say, it happened in the middle of sending. I got to about recipient 414, and got the "Error sending email. Please check outgoing email settings". Since then, nothing I do will allow this message to continue sending. I suspect that if I created a brand new message it would send just fine, but then 414 people would get a repeat message.

    Thanks.

    Danita

  • Vaughan

    Hi,

    Email errors like this are pretty hard to debug. You are actually better of sending in batches, say a couple hundred every 15 mins maybe?

    I'm a little unsure of whether this issue comes from the plugin SMTP sending protocol, or whether it could be coming from the mail server, maybe config settings, queue control or anti-spam settings on the mail server when receiving relayed mail.

    Let me just ask one of the developers for some advice on this for you. Hopefully he might have a better idea of how to debug this issue for you if possible.

    Thanks

  • Hoang Ngo

    @Danita,

    I hope you are well today.

    Hmm, interesting. Can you please let me know more about the configuration of your mail server, example what's the application you are using for sending mails, how it configured, etc. I strongly think this is a mail server issue rather than plug in issue.

    At the stage those errors came up, the mail plug in already could contact to your mail server, and then something happens. The mail server can't send more emails, and it back with those errors.
    Alternatively, something happens on your server with WordPress install, when the plug in trying to connect to the mail server for sending, some issues happen, make the connection fail, and you can get the same errors.

    Best regards,
    Hoang

  • Danita

    Hi Huang,

    I think it has to be on the Wordpress server, because I don't see any errors in my mail server log (I don't even see connections from the Wordpress server during these problems). I'm an email consultant, so I KNOW that my server doesn't have any sending limits, is not blocking the server for any reason, etc. I use Novell GroupWise SMTP service, I have it listening solely on port 26 (just for security by obscurity purposes) and can monitor the connections to that server very well. Since I'm not listening on any "standard" smtp port, it would be very unlikely (although not impossible) that any ISP would monitor and limit connections from the ISP level. I think something was simply stuck, because as soon as I switched from manual send to cron the messages just flew out of the eNewsletter system, one every 1 second. In other words, I put no practical throttle on the sending, and all 1200 remaining messages went in short order.

    If there were actual SMTP conversation logs from eNewsletter that I could look at, I could no doubt find the issue, but there seem to be no user accessible logs for the system at all.

    Thanks

    Danita

  • Hoang Ngo

    HI @Danita,

    I hope you are well today.

    I found a place we can enable the email status logging. In the file /e-newsletter/email-newsletter-files/class.functions.php, line 2433, you will see a code block like this

    function write_log( $message ) {
            if(!$this->debug)
                return false;
    
            $file = $this->plugin_dir . "email-newsletter-files/debug.log";
    
            $handle = fopen( $file, 'ab' );
            $data = date( "[Y-m-d H:i:s]" ) . $message . "\r\n";
            fwrite($handle, $data);
            fclose($handle);
        }

    Please update it to

    function write_log( $message ) {
            $file = $this->plugin_dir . "email-newsletter-files/debug.log";
    
            $handle = fopen( $file, 'ab' );
            $data = date( "[Y-m-d H:i:s]" ) . $message . "\r\n";
            fwrite($handle, $data);
            fclose($handle);
        }

    This will force the plugin to write logs for debugging. Let's see if it can give us some clues :slight_smile:

    Best regards,
    Hoang

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