What is SMTP Relay and when should I use it?

Luke .

If you are looking for a way to improve the reliability of the emails that your website sends out, be it a contact form, forum notification or that vital order email to a customer then setting up SMTP relay for your site is a very effective way to do just that. Here we go through what SMTP relay is and how it works…

What is SMTP relay?

SMTP stands for Simple Mail Transfer Protocol and is the most common standard used for sending email across networks and the internet. Acting like a post office of the online world, the protocol allows email to be transmitted and delivered over the internet. With an SMTP relay in place, you can rest assured that sent mail is going where it should be going.

SMTP relay allows you to route your website generated emails through an external server or network.  There are many services out there that offer SMTP relay services such as SendGrid/ Amazon SES/ Office 365/ Google Apps/ SparkPost/ MailGun to name a few.

So why would you want to relay your websites email through an SMTP relay service?

Your webserver with Nimbus is likely to only have one IP address for outgoing email. If anything happens to the reputation of your servers IP address due to it being flagged for spam or it being blocked, then the likelihood is that you will have a lot of email bouncing and not reaching those all-important customers.

By using one of the example services listed above, all of your website generated email gets routed through the relay providers servers which utilises a multi IP infrastructure for outgoing mail. If one IP gets blocked they swap in another straight away. Effectively the likes of Amazon, Google and others have infrastructure set up that’s been designed from the ground up to handle email.

SMTP relay is also a great way to prevent your websites email from going into the recipients junk/spam folders. It only takes a very small amount of your websites emails to be flagged as spam for subsequent emails to then be sent to the spam for all of your recipients. In recent years there has been a massive crack down on spam being sent via email across the internet. A lot of large email account providers such as Google and Microsoft have become extremely strict with their spam filtering policies and it’s not uncommon for them to flag an email as spam if it’s come from a single IP even if your server isn’t sending out spam.

Although for your business mailboxes we recommend using an email application service such as the g-suite offering from Google, Office 365 or the free ZOHO mail – SMTP relay is a great way to receive mail generated through your website such as contact forms or sign up forms and notifications on your web server.

SMTP Relay

How do I set up SMTP relay for my site?

This varies depending on the provider you choose and the CMS your website uses but the first thing to do is to sign up with an SMTP relay service provider. Once you have done this they will provide you with the settings you need to use to relay your mail through their servers. You will then need to configure your website to use SMTP rather than PHP mail or local mail by updating your sites code. This can be done very easily if the CMS you use is Magento or WordPress.  Both Magento and WordPress have a large number of extensions/ plug-ins that make setting up SMTP relay very easy. Here are a few example guides for setting up SMTP Relay on your email server:


SMTP Pro Email – https://www.magentocommerce.com/magento-connect/smtp-pro-email-free-custom-smtp-email.html


Easy WP SMTP – https://en-gb.wordpress.org/plugins/easy-wp-smtp/
Webriti SMTP Mail – https://en-gb.wordpress.org/plugins/webriti-smtp-mail

If you have any questions about setting SMTP Relay up on your Nimbus server please get in touch!
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