Bounces have gone from 0 to hundreds in past 2 days

[Jof]

Hoping someone may be able to help.

To my knowledge I keep a clean database of email addresses, and manage my SMTP sever reputation (SendGrid) to an excellent standard.

After using Mailwizz for a year my bounces on each campaign (I send several a day) is always 0. However in the past 2 days my bounces are now in the hundreds.

Does anyone know if anything has changed systemwide? I'm using Version 1.9.28 - 2021-04-06 since install. I've been using SendGrid as my SMTP server since install, and have changed literally nothing in my process, certainly not in the past 2 days, and probably months. I'm using (apart from 1 instance), the exact same Mail list i use everyday.

I've checked SendGrid, and the bounces haven't increased in line with what MailWizz Reports.

Any thoughts?

Many thanks,

J

 

[twisted1919]

From the looks at your screenshot, it just seem lots of your subscribers simply don't have those email addresses valid anymore.

 

[Jof]

Thanks for looking, but for me the odd thing is I've gone from literally 0 bounces, every campaign, for the past year, to hundreds per campaign in the last 2 days. The Excel export is SendGrid's bounce report (unedited), showing all bounces back to 10th Feb 2022 (17 total). Whereas MailWizz is showing 764 for one campaign sent today alone.

 

[twisted1919]

The internal bounces aren't a bad thing, see: https://www.mailwizz.com/kb/internal-bounces/
You can take this to SendGrid and ask them what is going on, maybe they're emails are rejected and this is the result which affects you as well.

 

[Jof]

The internal bounces aren't a bad thing, see: https://www.mailwizz.com/kb/internal-bounces/
You can take this to SendGrid and ask them what is going on, maybe they're emails are rejected and this is the result which affects you as well.

FWIW I've just had a long chat with SendGrid. It would appear they've always been reporting and keeping info on bounces on their end, but that info has not been coming through to Mail Wizz. Looking back on my Mailwizz campaign logs, I have 100's of bounces per campaign from Jan 2021, when we started using the system, and through list management these drop to 0 by 9th Aug 21. I have a few more campaigns with bounces on 24th/25th Aug 21. Then nothing until late November until 13 Dec 21. Then again, after that 0 bounces per campaign until 15th Feb 22. SendGrid say they haven't changed anything in their API that would affect how bounces are reported, and they've always had bounces on every campaign. But for whatever reason that info has never gotten to MailWizz.

 

[Jof]

I've also sent a campaign today, SendGrid reports bounces. MailWizz now reports 0 Bounces, SendGrid tells me 379 and counting.

 

[twisted1919]

I've also sent a campaign today, SendGrid reports bounces. MailWizz now reports 0 Bounces, SendGrid tells me 379 and counting.

Ask SendGrid for logs, what happened when they posted this information to your mailwizz app?

 

[Jof]

Thanks. What kind of logs? I've downloaded their send reports, and looked at the not delivered. I can see every campaign has bounces (understandable), but that not all bounces are reported back into Mailwizz. They say their API hasn't changed.
FYI my message at Wednesday 4:47PM is incorrect. I say SendGrid only reported a few bounces for a campaign. That's incorrect, the report mentioned there was just showing NEW email addresses that have bounced.

To be absolutely clear, from what I can see. Every campaign has bounces reported in SendGrid. Not every campaign in MailWizz reports bounces.

All other report information seems correct.

Thanks

 

[twisted1919]

That's incorrect, the report mentioned there was just showing NEW email addresses that have bounced.

To be absolutely clear, from what I can see. Every campaign has bounces reported in SendGrid. Not every campaign in MailWizz reports bounces.

I think the reason my be the fact SendGrid keeps a local list of bounces and they will only post it to MailWizz only once, then even if the email will bounce in future, they will not post it to MailWizz anymore, that's something you can ask them to be sure, I am just speculating now.

Looking at the list, there are a lot of internal bounces, which MailWIzz allows resending to, but if SendGrid does not, then this explains the behavior, so basically you send an email, that email will bounce, let's say because of "Envelope Blocked" error. SendGrid will record the bounce and send it to MailWizz. MailWizz will treat it as internal bounce, because this is a problem only with SendGrid, if sending from Mailgun for example, it might work, so MailWIzz simply reports the bounce and hopes next time when sending the email to this address the problem is corrected. But it isn't, because whatever reason SendGrid didn't fix the problem, then when the email returns SendGrid doen't send it to MailWizz anymore because it considers it already had done this in the past.

If this isn't plausible, we'll have to do some research to see what is going on, but if you say you get bounces for new emails, then my hunch is this is the problem.

 

[Jof]

I'm not sure I follow. And I'm a bit lost with it to be honest. It looks like the behaviour is quite erratic. Bear in mind I'm always sending to the same list. Here's the campaign reports from Mailwizz for the last few days. 0, hundreds, back to 0. I've no idea what's going on.

 

[twisted1919]

It actually aligns with my above statement. You were getting bounces because SendGrid had issues.
MailWizz marked those as internal bounces which allows resending.
Now SendGrid fixed their delivery issues and emails go out without problems.