Queeing and Mautic Logic

I have a logic question inside Mautic.

If Mautic is set to send mails with a Queue and limited to 10 messages limit, with the cronjob set to send every 5 minutes (so 120 messages per hour, 2880 message per day).

Now a drip campaign is setup to send the first mailer to a segment (segment size 40K) and then a day later second mailer.

Will mautic be able to send out the second mailer after a day ? First mailer will have only have sent 2880 mails out of 40K when the trigger to send next mailer out. Or will Mautic first try and send all the 40K out, and only after this start processing and sending mailer 2 ?


Why would you do that? Why not just set the msgs limit to a greater number and avoid any possible conflict?

Hey Yosu,

Firstly thanks for replying (I can always count on you in the forum and slack :slight_smile:)

Testing purposes of an ESP for rate limitations, but take for example a database of 1M records. I just want to try and understand the logic in mautic and the possibilities of different mailing techniques.

For anyone that is reading found an interesting thing that happened here.
Mautic went and started creating all the messages to be queued in /mautic/app/spool/default/
as it was a segment of 40K, it created so many files that the directory grew to over 3.6GB and ended up killing my hard disk space. Basically left me totally crippled and spent 3 hours trying to find out what it was that was eating the disk space as my DB size was only 500MB. Finally saw this little bugger and could not even delete the files as I had no space.

So a word of warning to anyone that is going to try this… think about disk space

wow, that’s interesting. Thanks for the info.

I am also interested in the original question about Mautic queuing and email sending mechanics. So if someone knows, please share :slight_smile:

it is a bit of a mystery for me still. Today I saw that some of the second mailers went out, but I am not sure how the spool is actually working…

@Yosu_Cadilla, when using Sendgrid API what is the max “Message limit for queue processing” and how often can you let a cronjob handle it?
We are switching from php mail to sendgrid at the moment and need to be able to send 10k batches of email.
Do you have a recommendation for this?

so from what I am seeing, and the only way for me to get any idea is to look through messages on SendGrid (subject line) and what it seems that what Mautic spool is doing is sending the first 1440 messages to email one, then it sends the second email, so email 1 is stopped for the day.

Big problem and what is so strange is that for each queue that is created mautic creates a file with the html and details inside, as said it ate up my disk space and I was on 65K files in spool

yes every email is queued as a seperate file so that should be right

Elastic Email is one of the email gateways that is fairly lenient on sending large volumes of email from a new account, as opposed to say, SparkPost that has a very strict limitation until you’ve built up a positive sender reputation with them. Amazon SES, especially with the new API support in Mautic, is also worth a try.

I don’t know if there is a sending speed limit on Sendgrid or how to increase it.
My suspicion is that the more you pay, the larger the “Pipe” you get.
On a “Pro” Account, via Sendgrid API, I was able to send 160K emails in about 2 hours (no queue).
That makes for about 22 emails per second, which is also about the same “default allowance” that you get on AWS SES for example.

My recommendation, since you are paying the premium Sendgrid prices, use the API, do not use the Mautic queue, enjoy blasting speeds… ( Sendgrid might take 2 hours to send those emails out, but via API it will swallow all the emails from Mautic very, very fast, just a few minutes).

OH! the major problem of doing this is that you loose the ability to stop sending emails, so if you made a mistake, the emails go out so fast, there’s no way to stop the sending once they reach Sendgrid’s processing, which happens almost immediately.

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We have now set Mautic to use Sendgrid with smtp and send inmmediately and did a test with 7k emails and they were send quite fast. But you recommend do use the API as that will be even faster?

Indeed, API is 10-20 times faster than SMTP (on Sendgrid or on any other provider).

SMTP is about as old as the Internet and as slow as a 24K modem, lol.


Hmm… I have none technical knowledge, so I must asking. I talked with Elastic Mail support. Elastic mail have got integration with Mautic only by SMTP. They said me that Elastic Mail have to sending a huge e-mail campaigns like 1000 mails/s with this connection. I did’t test it. Maybe they were wrong?

This is a old post so I’ll add my observations here in case it helps anyone. We use Sparkpost and Elastic Email via API. Sparkpost is the speed champ with more than 1,000 emails in under a minute. Elastic Email seems to take around 5 minutes per thousand. Both examples are using the browser sending option. As i understand it, queuing is faster…