Newsletter to 2 mil+ contacts

Hello all,

I read a few topics and Github issues, but none seem to have provided an answer to our current problem/situation. I was hoping someone could provide us with some insight.

We have about 2 million contacts in Mautic, self-hosted. We successfully sent a few segment e-mails with smaller groups.

Now we’re about to send a newsletter to all our contacts, like this;

  • Channels / Emails, we pick a segment that contains all the contacts (a lot) and the mail template is set up right. But then when we click ‘Send’, it asks for batches, and if say we choose a 1000 a time, one of us will have to keep the page open for a really long time for Mautic to queue all the e-mails? This feels wrong coming from Mailchimp.

We are using the Amazon SES API which has plenty of room for one newsletter a day limit-wise.

I tried upgrading the EC2 and the RDS where the DB resides, and it has no effect.
EC2 load seems well below 50%, same with the current RDS setup. No disk wait etc.

We’ve also tried using the ‘Queue with Filesystem’ option, which apparently still gives the ‘sending in batches’ screen, which also takes a long while to fill up… while we kinda hoped everything would be running in the background by a cronjob with this option.

My Mautic version is: 3.2.5
My PHP version is: 7.4.13
My Database type and version is: MySQL 8.0.20

It’s to be expected that it would take a few hours to send out this many e-mails, which is no problem. But the main issue here is that it seems like someone needs to keep the “Sending X of X…” page open for a long time?

So is there another approach for a newsletter with this many contacts, or is something bottle-necking on our side? If someone needs more info, happy to provide.


Please read my article about this:


Hey, oh thanks so much! I didn’t come across that topic. It should be something for the documentation! :slight_smile:

The mautic:broadcasts:send command really helps, that solved our biggest issue with queueing up the e-mails, so considering this. Our problem is solved… now we run into the problem that it’s taking too long to send out 2mil e-mails. But I’ll continue in your thread about that :slight_smile:

I want to ask you how is your expeirnce with SES, I used regular shared hosting to send emails and my emails never arrive to gmail inbox. So my customers dont get my emails. If I uses SES will my emails be inboxed to gmail?

Inboxing is a tricky thing. But you’ll have better chances of inboxing for sure. I had a video about this during the Mauticon: MautiCon 2020 - József Keller - Be a Better Emailer - YouTube

do you think DKIM and PDIF really help? Or is just BS?
My emails dissapear when I send them to gmail, they dont even get stuck is SPAM, what kind of service is GMAIL giving to people if the loose emails…so now I use gmail to send to gmail to inbox…disaster, like they do it on purpose

So far we’ve had a great experience with SES. We first moved off SendGrid with all of our transactional e-mail (welcome mail, reset password, order confirmations etc.), to slowly build up a good reputation at SES.

Now we also moved our newsletter and campaigns from Mailchimp to SES (with Mautic), and so far we still have an healthy reputation on SES. We also process unsubscribes/bounces automatically, to keep it that way.

Haven’t had any complaints from our users thus far :slight_smile:

And regarding the DKIM, SPF records, not sure if they really help but I think it certainly wouldn’t hurt to have them set up properly…

Shared hosting is harder, since they tend to use either your account IP or a shared IP which may have been abused by others on the same hosting. With SES you can also choose to get a dedicated IP to protect your reputation, or just the ones from Amazon which Amazon tends to keep ‘healthy’ themselves. We opted for the latter, since we send out a lot of e-mail and if it’s coming from a “new ip” mail providers tend to see it as spam. Just our experience with e-mail over the past years, feel free to correct me anywhere.

We’ve sent about 3.1 million mails over the past 3 months through SES, not one complaint about the delivery from our users (and they tend to complain fast :wink: )

Amazon SES works fine. I also use it and never had problems.

If you care about email deliverability you must configure DMARC, DKIM and SPF records.

You shouldn’t be angry at Gmail. If you send emails without caring for the basics than your emails deserve to disappear :wink:

I love Amazon SES. We are sending about 50k outreach emails (aka SPAM) a day and we still have a good reputation…

I have setup SPF and DKIM on my domain and still the email dissapears!!! Is not even in spam!
Can I send you email so you can check it out?

Also that video that is posted above, the person in the video claims that your domain can be ruined and useless and all I did is send newsletter to double optin subs…real subs, no spam…

Did you also configure DMARC?

Regardless of things like DMARC, SPF and DKIM records… Email usually does never just disappear. Never.

If your sending server sucks and has a bad reputation it can happen that the smtp server that has to receive your email refuses the email, it will bounce, and you will get a notice about that on the email address in the From or Reply-to header. But it will not disappear without getting a notice.

If your domain has a very bad reputation, or there is something very wrong with the content of your email the email can go to SPAM. But it will not disappear.

Does only email to gmail disappear? Or also to other email addresses?

You can send me a PM here…


dmarc is missing, my host does not know how to set it up
it does, I never got a bounce-back email I send to my own Gmail accounts, it is not in spam, or junk and does not get inboxed…
it arrives on other emails besides Gmail, so it is sent out.

If you send an email to do you get a bounce email saying that the email address does not exist?

DMARC is very easy to setup yourself. And you can add it to the DNS also yourself.

where do you host mautic? On aws?

Yes AWS, we have Mautic running AWS;

  • One m6g.xlarge currently for the front-end/cron-jobs. But I think we can downgrade that instance, since it’s not using that much… even when we send out a newsletter to 2 mil+ contacts.

  • One RDS for the DB, that is currently db.r6g.2xlarge (64 GB ram), since we saw a lot of disk activity so we were afraid there wasn’t enough RAM for the DB.

We’re still looking into increasing performance there, since browsing segments and sent e-mails is slow sometimes and building segments also takes some time. But it all seems to be mostly the DB. We’re also gonna look into Amazon Aurora, for hopefully some increase in performance on the front-end as well. Also hoping some upcoming PR’s/releases will increase some query performances :slight_smile: