How do I setup outgoing e-mail?

To send e-mail, an e-mail server is required.
By default, the i-Reserve application comes with a built-in email server.
Nothing needs to be set for this.

There can be several reasons to use a different email server.
The most commonly used reason is to increase the chance of delivering the email correctly. in other words to prevent the e-mails from ending up in the junk e-mail.

A separate configuration page is available for setting up outgoing e-mail.
This can be found in Configuration > System > Outgoing email.

Roughly there are a few sets of settings.

Mail server

Setting up another mail server is done by a set of settings that belong together.
For example, a Host+Port is required to connect to and a username+password for authentication.
In addition, the connection may need to take place via SSL.
The administrator of the mail server should provide this information.

DKIM

DKIM can be used to "sign" the emails.
With DKIM, the sending server (i-Reserve) uses a 'private key' to create a cryptographic signature and add it to the mail in the form of a so-called DKIM header. A kind of authenticity feature.
In the DNS you set the 'public key' that the recipient uses to check the authenticity feature. Then the private key can be set in the "DKIM private string" field so that outgoing mail is signed and the receiving server uses the already published public key to validate this.

The set of DKIM usually consists of a domain + selector + private key.
These can be created for example via https://www.zerobounce.net/services/dkim-generator .html

The private key field normally contains a start and an end tag. In the form of "-----BEGIN RSA PRIVATE KEY-----" and "-----END RSA PRIVATE KEY-----"