smtp/connection: relax ssl/tls options passthrough

Readme.md

@@ -165,13 +165,15 @@ const options = {
 	password, // password for logging into smtp
 	host, // smtp host (defaults to 'localhost')
 	port, // smtp port (defaults to 25 for unencrypted, 465 for `ssl`, and 587 for `tls`)
-	ssl, // boolean or object {key, ca, cert} (if true or object, ssl connection will be made)
+	ssl, // boolean or object (if true or object, ssl connection will be made)
 	tls, // boolean or object (if true or object, starttls will be initiated)
 	timeout, // max number of milliseconds to wait for smtp responses (defaults to 5000)
 	domain, // domain to greet smtp with (defaults to os.hostname)
 	authentication, // array of preferred authentication methods ('PLAIN', 'LOGIN', 'CRAM-MD5', 'XOAUTH2')
 	logger, // override the built-in logger (useful for e.g. Azure Function Apps, where console.log doesn't work)
 };
+// ssl/tls objects are an abbreviated form of [`tls.connect`](https://nodejs.org/dist/latest-v14.x/docs/api/tls.html#tls_tls_connect_options_callback)'s options
+// the missing items are: `port`, `host`, `path`, `socket`, `timeout` and `secureContext`
 // NOTE: `host` is trimmed before being used to establish a connection;
 // however, the original untrimmed value will still be visible in configuration.
 ```
@@ -240,13 +242,15 @@ const options = {
 	password, // password for logging into smtp
 	host, // smtp host (defaults to 'localhost')
 	port, // smtp port (defaults to 25 for unencrypted, 465 for `ssl`, and 587 for `tls`)
-	ssl, // boolean or object {key, ca, cert} (if true or object, ssl connection will be made)
+	ssl, // boolean or object (if true or object, ssl connection will be made)
 	tls, // boolean or object (if true or object, starttls will be initiated)
 	timeout, // max number of milliseconds to wait for smtp responses (defaults to 5000)
 	domain, // domain to greet smtp with (defaults to os.hostname)
 	authentication, // array of preferred authentication methods ('PLAIN', 'LOGIN', 'CRAM-MD5', 'XOAUTH2')
 	logger, // override the built-in logger (useful for e.g. Azure Function Apps, where console.log doesn't work)
 };
+// ssl/tls objects are an abbreviated form of [`tls.connect`](https://nodejs.org/dist/latest-v14.x/docs/api/tls.html#tls_tls_connect_options_callback)'s options
+// the missing items are: `port`, `host`, `path`, `socket`, `timeout` and `secureContext`
 // NOTE: `host` is trimmed before being used to establish a connection;
 // however, the original untrimmed value will still be visible in configuration.
 ```

smtp/connection.ts

@@ -1,8 +1,9 @@
-import { Socket } from 'net';
 import { createHmac } from 'crypto';
+import { EventEmitter } from 'events';
+import { Socket } from 'net';
 import { hostname } from 'os';
 import { connect, createSecureContext, TLSSocket } from 'tls';
-import { EventEmitter } from 'events';
+import type { ConnectionOptions } from 'tls';
 
 import { SMTPError, SMTPErrorStates } from './error';
 import { SMTPResponseMonitor } from './response';
@@ -66,11 +67,10 @@ const caller = (callback?: (...rest: any[]) => void, ...args: any[]) => {
 	}
 };
 
-export interface SMTPSocketOptions {
-	key: string;
-	ca: string;
-	cert: string;
-}
+export type SMTPSocketOptions = Omit<
+	ConnectionOptions,
+	'port' | 'host' | 'path' | 'socket' | 'timeout' | 'secureContext'
+>;
 
 export interface SMTPConnectionOptions {
 	timeout: number | null;