fix: removed invalid options for the sendmail transport (#8576)

* Removed invalid options for the sendmail transport that were causing Nodemailer to return the SMTPTransport instead.

* Removed options for rate limiting in admin email interface. Added new option for toggling whether to use pooled connections.

install/data/defaults.json

@@ -110,8 +110,7 @@
     "maximumInvites": 0,
     "username:disableEdit": 0,
     "email:disableEdit": 0,
-    "email:sendmail:rateLimit": 2,
-    "email:sendmail:rateDelta": 1000,
+    "email:smtpTransport:pool": false,
     "hideFullname": 0,
     "hideEmail": 0,
     "allowGuestHandles": 0,

public/language/en-GB/admin/settings/email.json

@@ -4,9 +4,6 @@
 	"address-help": "The following email address refers to the email that the recipient will see in the \"From\" and \"Reply To\" fields.",
 	"from": "From Name",
 	"from-help": "The from name to display in the email.",
-	"sendmail-rate-limit": "Send <em>X</em> emails...",
-	"sendmail-rate-delta": "... every <em>X</em> milliseconds",
-	"sendmail-rate-help": "Instructs the NodeBB mailer to limit the number of messages sent at once in order to not overwhelm email receiving services. These options do not apply if SMTP Transport is enabled (below).",
 	
 	"smtp-transport": "SMTP Transport",
 	"smtp-transport.enabled": "Use an external email server to send emails",
@@ -25,6 +22,8 @@
 	"smtp-transport.username": "Username",
 	"smtp-transport.username-help": "<b>For the Gmail service,</b> enter the full email address here, especially if you are using a Google Apps managed domain.",
 	"smtp-transport.password": "Password",
+	"smtp-transport.pool": "Enable pooled connections",
+	"smtp-transport.pool-help": "Pooling connections prevents NodeBB from creating a new connection for every email. This option only applies if SMTP Transport is enabled.",
 
 	"template": "Edit Email Template",
 	"template.select": "Select Email Template",

src/emailer.js

@@ -25,9 +25,6 @@ Emailer.transports = {
 	sendmail: nodemailer.createTransport({
 		sendmail: true,
 		newline: 'unix',
-		pool: true,
-		rateLimit: meta.config['email:sendmail:rateLimit'],
-		rateDelta: meta.config['email:sendmail:rateDelta'],
 	}),
 	smtp: undefined,
 };
@@ -66,7 +63,9 @@ Emailer.setupFallbackTransport = function (config) {
 	winston.verbose('[emailer] Setting up SMTP fallback transport');
 	// Enable Gmail transport if enabled in ACP
 	if (parseInt(config['email:smtpTransport:enabled'], 10) === 1) {
-		var smtpOptions = {};
+		var smtpOptions = {
+			pool: config['email:smtpTransport:pool'],
+		};
 
 		if (config['email:smtpTransport:user'] || config['email:smtpTransport:pass']) {
 			smtpOptions.auth = {

src/views/admin/settings/email.tpl

@@ -18,19 +18,6 @@
 				</p>
 				<input type="text" class="form-control input-lg" id="email:from_name" data-field="email:from_name" placeholder="NodeBB" /><br />
 			</div>
-			<div class="row">
-				<div class="form-group col-sm-6">
-					<label for="email:sendmail:rateLimit">[[admin/settings/email:sendmail-rate-limit]]</label>
-					<input type="number" data-field="email:sendmail:rateLimit" id="email:sendmail:rateLimit" class="form-control" placeholder="2" />
-				</div>
-				<div class="form-group col-sm-6">
-					<label for="email:sendmail:rateDelta">[[admin/settings/email:sendmail-rate-delta]]</label>
-					<input type="number" data-field="email:sendmail:rateDelta" id="email:sendmail:rateDelta" class="form-control" placeholder="1000" />
-				</div>
-				<p class="col-xs-12 help-block">
-					[[admin/settings/email:sendmail-rate-help]]
-				</p>
-			</div>
 		</form>
 	</div>
 </div>
@@ -50,6 +37,17 @@
 					<span class="mdl-switch__label">[[admin/settings/email:smtp-transport.enabled]]</span>
 				</label>
 			</div>
+			<div class="form-group">
+				<div class="checkbox">
+					<label for="email:smtpTransport:pool" class="mdl-switch mdl-js-switch mdl-js-ripple-effect">
+						<input class="mdl-switch__input" type="checkbox" id="email:smtpTransport:pool" data-field="email:smtpTransport:pool" name="email:smtpTransport:pool" />
+						<span class="mdl-switch__label">[[admin/settings/email:smtp-transport.pool]]</span>
+					</label>
+				</div>
+				<p class="col-xs-12 help-block">
+					[[admin/settings/email:smtp-transport.pool-help]]
+				</p>
+			</div>
 			<div class="form-group">
 				<label for="email:smtpTransport:service"><strong>[[admin/settings/email:smtp-transport.service]]</strong></label>
 				<select class="form-control input-lg" id="email:smtpTransport:service" data-field="email:smtpTransport:service">