Sending Newsletter

Hello.

I have a problem / doubt about sending newsletters. I use Mautic in version 2.16.3 and I configured the smtp server using the Amazon service. The configuration is correct and has been tested.

Last week I sent a newsletter to 450 contacts and everything went smoothly, but today I sent one to all my contacts (25,000) and, despite the fact that all the emails have been sent, none of this is read.

Can you give me suggestions?

Hi, SES send SMTP sending well with Mautic. (On an other note, just for sending newsletters Mautic is not the best tool…)
Please check if you see 25k emails sent in your SES console.
If you see, that not all it is sent, check if you have any issue with rate limiting.
read this post:

It can happen, that your server is sending too fast, which can make your account throttled or the whole send just smokes away. That means Mautic thinks it’s sent, and Amazon just claims it never got them because the ‘door was already closed by them’.

Good luck

Thank you very much for your reply.

Best regards
Giancarlo