SMTP an IMAP email settings


Rocket Chat installed on September 13, 2022.
Used SNAP installation and online install documents

Server Setup Information

  • Version of Rocket.Chat Server:
  • Operating System: Ubuntu 20.04.5 LTS
  • Deployment Method: SNAP
  • Number of Running Instances: 1
  • DB Replicaset Oplog:
  • NodeJS Version: V18.9.0
  • MongoDB Version:
  • Proxy: nginx reverse proxy
  • Firewalls involved:

Any additional Information

not needed

In the admin setup from Rocket.Chat email sending parameters can be entered.
What is tested:
SMTP port 25 with user name and passwd > working
SMTPS port 438 with user name and passwd > receive garbage email

EHLO send IP address
Host send public IP address from the server

Request to send with EHLO the server name or self created name
Request to send HOST information same name as EHLO

As extra remark, in the send test email I see a placeholder for a picture or logo.
Please make this to upload a logo or place the logo there



Hi! Please, state what version you are at.

Also, increase the log verbosity (Admin > Logs) and then try sending an email test so you can try to catch some logs.


Hi dudanogueira,

Rocket.Chat Version: 5.0.6
NodeJS Version: 14.19.3 - x64
MongoDB Version: 4.4.15
MongoDB Engine: wiredTiger

The extendend log file option does not show what is send to the mailserver
RocketChat send the public IP address to the mailserver instead of the domain name
As EHLO name is send the local ip address instead of a name like Rocketchat

Please change those things as IP addresses are blocked by many mailservers


Under the hood, we use nodemailer:

You can overrride all nodemailer configurations by changin the MAIL_URL environment, that is built with the settings you define in Rocket.Chat.

Can you provide a MAIL_URL to nodemailer that will work?


Rocketchat is brandnew for me,
But I wonder why things are become needless complicated?
Why need a other program, that can’t be find in the rocketchat cloudstore, to solve a issue that can be solved inside Rocketchat.
It is nice you point me out to use this Nodemailer but then make it complete and tell me how to implement this in the snap configuration as I do understand that snap is a isolated runtime environment.
In the mean time I work and configure Rocketchat I found several things who are not logical and will produce miss understandings.
The most hot issue is the used Mongod database with many errors in the logfiles and need a lot of search to solve it. Even from this database there is documentation how to list database and collections but no information about how to see what is stored in the collections.
I spend hours to find out how to list contents, but failed as all commands return empty information within the mongsh shell.
The second issue is the connection with rocketcloud, which are not clear how it works and which credentials are used to make the verified connection.
Deleting the community instance still leaves information excisting which don’t allow a second new installation, with the same credentials, to make connection.
It is frustrating for me to jump from one problem into a other without proper information how to solve issues.
I hope you understand my feelings

With friendly regards,


Hi Ronald!

Thanks for your input.

You are using snap for deployment. While this works great and is a quick way to get it up and running, we suggest all users to move to a docker or k8s deployment, as you will have a more similar environment as other users.

With that you may not have some of the mongo errors you mentioned.

We have improved the cloud registration process a lot, and making it going from the initial setup wizard. If you have chosen the standalone, you can still register it from the ADMIN > Connectivity Services.

For the nodemailer, what I mean is that, Rocket.Chat uses the nodemailer. You don’t need to install it.

While the config interface is enough for the vast majority of users, some SMTP server will require specific configurations. Rocket.Chat is flexible enough to allow you to pass those specific configurations directly into MAIL_URL, following nodemailer specifications.

Please, let me know if this helps!


This exactly my point, there are not enough fields to change the required information.
I use Mercury Email, and like that the requirements are meet by Rocket chat
That means not sending any IP addresses but names

It is nice you advice nodemailer but I don’t like to use it


Hi, not sure you understand.

Rocket.Chat uses nodemailer.

The basic setup can be done using the GUI.

For more advanced configurations, you will need to craft your own MAIL_URL, and pass it as an environment variable.

With that said, nodemailer allows a lot of options on it’s config URL: