Let’s all admit it, our emails are our babies, we spend hours crafting our subject lines, days picking up the perfect font and size, assembling templates, editing them to finally proudly give birth to our masterpiece. We love a well drafted email and we never feel prouder and more satisfied than after hitting send to a gorgeous email. On the other hand, we all know how heartbreaking and atrocious it is to know that our recipient never had the chance to open our email.

According to the 2015 Deliverability Benchmark Report, worldwide, just 79% of commercial emails land in the inbox. This means for every five emails sent, one never reaches the intended recipient. Instead, it’s either sent to the spam folder or goes missing—most likely blocked by the mailbox provider.

No matter how gorgeous your emails are, or how marvelous your email marketing strategy is, email deliverability is a crucial element that is today regulated by strict laws and increasingly sophisticated spam filters that you need to seriously consider and comprehend for the success of your strategy. But don’t worry we are here to walk you through the best practices you need to follow in order to insure your emails safely reach your recipient’s inbox. We’ll also go through few things that you should AVOID and that might result your email to never reach your destination.

Things you should NEVER do:

1- Buying or Renting Email lists:

The first rule to avoid spam folder is never buy or rent your email list. Buying or renting an email list might look as a good and easy option, yet it is never a good idea. A really good email list would never be for sale, so eventually using this email lists will either result in placing your emails in the spam folder or just turning them into hard bounces, since the people you’re contacting don’t know you, they never asked for your emails, and they simply don’t want them in their inboxes. Additionally, reputable email marketing vendors wouldn’t let you send emails to lists you’ve bought. So remember a great email list is never for sale, and a sold email list is never worth it.


You can see how annoying it was to read this title all in uppercase, it feels like I’m shouting at you, right? Well, this is a crucial thing to remember, don’t shout at your recipients. More than that, an all caps lock email looks spammy and machine generated, and you don’t want that. You want your subject line to sound as human and personalised as possible. And this is also applicable for exclamation points!!!! Be careful, a bunch of exclamation marks in a subject line look spammy and robotic, and you want to avoid that!!!!

3- Using Spam Flagging subject lines.

You subject line is your first thing your recipient judges you on, you don’t want to look spammy at first sight. Not only your subscribers might mark you as spam or just not open your emails, but also the spam filters ISPs. You can refer to Hubspot article on the the spam filter flagging keywords and make sure you don’t use them in your subject line.

4- Be Careful with your Email content

Here are few things you should consider before sending your emails:

  • Avoid interactive content like Java Script, RSS feeds, and forms. They could cause your email to be put in the spam folder.
  • Avoid using a lot of colours, weird fonts, or writing in big sizes. There are plenty of ways to be creative, don’t get creepy!
  • Don’t include too many images in your email.
  • Avoid using URL shorteners. Some of the shortened domains like bit.ly for example are put under “widely-used block lists” and eventually emails containing these links would be blocked by spam filters

What you should do:

Now that you know the things that could kill your deliverability we’re gonna move to the best tips we thought about in order to make sure your gorgeous email reach your audience’s inbox.

1. Constantly upgrading your email list

You don’t want to send your emails to people who wouldn’t open them. Make sure you send your emails to people who want them in their inboxes. Nothing is worse than an unwanted email. So constantly upgrading and filtering your email list allows you to stay in touch with people who actually want your emails, and eventually helps you avoid bounced emails. You can check our previous blog post on how to grow your email list for more tips and tools on upgrading your email database.

2. Protect your IP reputation:

The first goal you want to keep in mind in email marketing is avoiding being perceived as a spammer in the eyes of spam filters, and your audience, so one important thing you want to tackle is to gain a good IP reputation and maintain it. You can start your email campaign by sending few email to well engaged adresses. Your recipients will open and read and engage with your emails, and eventually your IP will start gaining trust and credibility with the ISP. Again we emphasise on keeping your focus on your email database as clean and updated as possible!

3. Keep track of your sender reputation:

An important reason why your email don’t reach your audience’s inboxes is a low sender score. The sender score is like a grade you get for your sender reputation, it’s on a 0 to 100 scale and it basically shows how your mailbox providers view your IP address. Sender Score is produced by Return Path and it is mainly calculated by using some traditional email metrics like number of unsubscribes or spam reports. You should consider keeping your sender score closer to 100. You can use other tools to check your sender reputation like Senderbase.org or ReputationAuthority .

4. Authenticating your emails

Authentication verifies the sender identity in a way, it makes sure that the email is actually coming from you or your business. It’s like setting your unique digital finger print. It protects customers but also your brand, identity and reputation. Email authentication is crucial to the improvement of your deliverability.
If your mail service happens to be unauthenticated you might face the following issues:

  • Your emails are directly delivered to your recipient Spam/Junk folders.
  • You get bounces from your email with an “SPF record failure’ error.
  • You get multiple ‘failed delivery’ bounce back of the emails that couldn’t be delivered.

You can check Campaign Monitor’s article on Email Authentication for more details about this process.

5. Use confirmed opt-in lists

Confirmed Opt-in -or double opt-in- is the strictest way to obtain permission to send email campaigns. It requires your potential subscriber to respond to an email confirmation in order to be added to your emailing list. It basically verifies the identity of your subscribers; it prevents people from subscribing false or malicious addresses to your list. As an ISP standard for managing mailing lists, it guaranteed an effective deliverability for your emails.