Cold email outreach is a tough gig. You collect a list of leads, craft the perfect email, and use automation software like Outreach to start conversations for you, but a lot of the time what you get back is… crickets.

It can be really hard to know what’s happening on the other end. Are your contacts simply not interested? Or are your emails getting lost in cyberspace?

More and more corporate emails are being sent through hosted solutions like G Suite or Office 365, but these platforms don’t provide you with tools to find out if your emails are being blocked by spam robots. In fact, they deliberately make it difficult to understand this to prevent you from getting around it.

But, thankfully, there are 5 ways you can check to make sure your business emails are reaching their destinations. This post will guide you through 5 checks you should run frequently if you’re sending cold emails to check if you’re in spam trouble.

(And if you discover that your emails are getting blocked, read our next post about how to fix spam issues with cold email here.)

1. The quick check.

First, a simple rule of thumb before we get more technical. If you’re getting a higher rate of negative replies than positive replies (ie. “remove me,” “take me off your list,” etc.) then you’re definitely heading straight for spam jail.

You may or may not be there already, but you’ll want to reverse your ratio of positive to negative replies as soon as you can.

2. Examine your email bounces.

When an email bounces, it will usually tell you why it bounced. If you read the bounced email, you’ll see a message ranging from “address does not exist” to “mailbox full.” Or you’ll get a bounce code that you can identify with a quick Google Search.

If the bounce reason is something like “message refused,” there’s a good chance your email was blocked somewhere along the way.

Whether you’re dealing with a bad lead list, or a server issue, or a spam issue, bounced emails are a good place to start investigating. Here’s an explanation of the different reasons why you might receive a bounce notification.

3. Check if your email domain is blacklisted.

There are a number of blacklist services that keep a record of domains that are suspected of spam activity (whether the jail time is deserved or not). Email providers filter out emails based on these blacklists, so if your domain appears on one there’s a really good chance your leads aren’t seeing your awesome copy.

You can easily check if your IP or domain is listed on blacklist services like Spamhaus, SURBL, Barracuda, and SpamCop. And there are tools like MXToolbox and Return Path that will check against multiple blacklists for you.



4. Use tools to check your deliverability.

Check your email deliverability by sending it to a spam checker service like GlockApps. It’s a useful tool that will show you the likelihood of your email reaching inboxes and will also help point out the reason why you might be running into trouble.

There are lots of email content triggers, for instance, from certain word combinations and links to spelling mistakes and formatting, that will send your email straight to spam. Or perhaps your problem is with your sender reputation or domain authentication.

GlockApps works by giving you a list of email addresses to send to, with different email providers, and then checks whether those email addresses receive your emails. If you find that number to be less than 70% then you have a spam issue.



5. Are your outbound results decreasing?

If your email campaign starts working well but after a while you start seeing a continued trend of lower and lower open rates, combined with low reply rates, there’s a pretty good chance you’ve been slapped with the spam stick, which means your emails aren’t getting delivered at scale.

Another great way to check this is to continuously track deliverability, sender reputation, and content score through tools like SendGrid and GlockApps.

You can try testing a completely different version of your email sent to the same contacts to see if you get a different result. If your results improve, the problem was likely your copy. If they don’t improve, the issue could be your domain.

It’s not always easy to figure out if you’re spam-free with a one-off check, so make sure you track your results on a weekly basis to see if they decrease.


Once you know you’re in spam trouble, you can do something about it.

When it comes down to it, there’s no way to ensure that your leads will receive your emails 100% of the time. Spam filters are constantly improving their algorithms and implementing stricter policies.

But what you can do is control the factors that may lead to your domain or email content being labeled as spam. Make sure you’re constantly using the checks above to observe the reaction your emails are getting from spam filters.

If you ran the checks in this article and found that your emails are getting blocked, check out our post about how to get out of spam trouble here.