how can i change smtp limits

[darsh_parsana]

hey guys so I am using Cloudron SMTP and I want to send 1000 mails concurrently but I see there are a few hard code limits set by Cloudron which is not editable, so how can I change these limits

Email access (Port 25, 465, 587, 993, 4190) - 50 connections per second per IP/App.
Email relay access - 500 connections per second per app.
Email receive access - 50 connections per second per app.
Auth addon access - 500 connections per second per app.
and smtp concurrent request limit in general

( not great with docker so please also share me the docker commands if i have to run any ) also, i tried updating an outbound.ini file inside docker but it was not writable

[micmc]

You'd rather use SMTP relays services for such use. I'd STRONGLY recommend it. Cloudron supports most of the most powerful ones out of the box.

[darsh_parsana]

yup I know i can, but I have few reasons why I want to increase current cloudron SMTP limits

[matix131997]

Maybe it is possible to set an increase in the limit.

But you need to keep this in mind by having a high email sending rate set at the same time, risk the reputation of the server's IP address and stronger blocking of email delivery at different recipient providers.

I recommend using an external SMTP to send "marketing" emails. This is the professional name for a service that sends more than 1,000 emails.

[darsh_parsana]

yup, it's not for sending marketing it's for something else, I just wanna know how can i increase the sending concurrent in in-build-smtp by cloudron

[matix131997]

That's not the point. Behind the SMTP service "E-mail Marketing" is constructed that the SMTP system sends thousands of e-mails uses different IP addresses even a whole pool of addresses.

I did not add above, about risking reputation. Large providers do not only add the IP address to the blacklist and even the domain you own if you send from one server. So it's a VERY high probability that you'll be blacklisted as an "unsafe domain" within days.

If it's a one-time situation then you have to wait patiently for a full upload using a constructed queue. Sending 1000 emails, even if you have half of the addresses from gmail and icloud for example, the system will mark as Spam or Hard Bounces.

[matix131997]

This is how I review your previous posts. You had a problem sending an email that was in the queue. That's just the charm of "Hard Bounces" email providers and that's why it didn't get sent.

That's why I or other users have written and will write, we recommend using SMTP to properly send all emails without any problems with Spam and Hard Bounces.

[girish]

@darsh_parsana these limits come from the firewall and not from Haraka/mail server and are there to prevent basic DoS attacks or buggy software.

Note that the limits are for TCP connections per IP and not for concurrent SMTP transactions. In general, you can always send 1000 mails concurrently provided mail container has enough memory and your server also has enough memory.

[girish]

If you really need this , you can always edit the file /home/yellowtent/box/setup/start/cloudron-firewall.sh and change the --connlimit-above values . There are two of them. Then systemctl restart cloudron-firewall

[darsh_parsana]

Hi Girish, thanks for the reply

i guess there is a limit in sending outbound emails ( buildin SMTP ) not sure

also can you tell me the proper docker command to edit this like which container and how to get inside the container

[BrutalBirdie]

@darsh_parsana

/home/yellowtent/box/setup/start/cloudron-firewall.sh is on the root system, not inside any container.
You can just edit the file directly via ssh.