The TL;DR on Email Deliverability for Recruiters

Looking for a quick & easy guide to all things email deliverability for recruiters? You came to the right place.

Make no mistake, though: Email deliverability is far from a simple concept. If you want to dive a bit deeper to make sure you fully understand the ins and outs, we've also got a deep dive on email deliverability for recruiters. Call it a "definitive guide," a "deep dive," or simply "my hero" — either way, it's designed to leave no stone unturned.

Here, on the other hand, we're giving you the SparkNotes version. Informative in its own right, but a lot less bulky.

Let's dive in!

Get your domain authenticated

Domain authentication is the process of verifying that the sender of an email is who they claim they are. It acts like a digital signature that confirms your email is legitimate and sent from a trusted source.

Monitor your domain reputation

Your domain reputation is like your credit score, assessing your trustworthiness. Use Google Postmaster Tools to keep a close eye on your domain’s reputation metrics.

Send to only validated email addresses

Validated email addresses are verified as active, accurate, and deliverable. This means the email address belongs to a real person who actively uses it and is capable of receiving your messages. When you send emails to invalid addresses, it results in bounces — emails that can’t be delivered because the recipient's email doesn’t exist or is no longer active. High bounce rates are a red flag for email providers like Google, indicating poor list management. These bounces can damage your sender reputation, reduce your deliverability, and cause your emails to end up in spam folders or get blocked altogether.

Watch your bounce rate

Maintain a bounce rate below 2% — good data hygiene is crucial in achieving this, which is why verifying & validating your email addresses before a send is key.

Send from trusted sources

When an email arrives from an unrecognized or suspicious sender, recipients are more likely to ignore it or mark it as spam (and we’ve already covered why you want to avoid that). Establishing a clear, recognizable sender identity is critical to maintaining both email deliverability and engagement. The right sender builds trust with recipients and improves open rates — because people are more likely to interact with messages from senders they recognize and trust. Makes sense, no?  

Send text-only emails

In contrast to visually enhanced or “brand-forward” HTML emails, text-only emails focus solely on delivering the message in its purest form. Text-only emails significantly reduce the risk of being flagged as spam or phishing attempts. Because without any images, flashy formatting, or embedded links, these emails are perceived as trustworthy and legitimate. Even something as small as a graphic in your email signature can trigger spam filters, pushing your message into the recipient's spam folder.

Keep your email signature simple

If you use the same signature across hundreds or thousands of emails, spam filters may flag your emails as suspicious — especially if multiple recipients mark your messages as spam. Key identifiers like your phone number, domain, or even a photo can become the “red flags” that cause your entire email to get flagged or blocked. Over-complicating your email signature with too many links, domains, or contact details can dramatically increase your chances of being marked as spam. Since this section of your email remains largely static across your campaigns, it becomes an easy target for spam algorithms.

Optimize for replies, not opens

Open rate tracking is a method used by email marketers to measure how many recipients open their emails. Typically, this is done by embedding a small, invisible image or pixel within the email, which gets loaded when the recipient views the message. This pixel then reports back to the sender that the email has been opened. If your emails contain open trackers, platforms like Google will notify the recipient that the email might be suspicious or spam by displaying a warning. This warning hides any images by default, including the tracking pixel, and encourages users to either ignore or report the email as spam.

Open rates alone aren’t a reliable measure anymore, and focusing on responses or click-through rates might provide a more accurate picture of your campaign’s success.

Include an unsubscribe option

Emails that make it difficult for people to opt out of future communications are more likely to face penalties, and with growing privacy regulations like GDPR, it's a fundamental requirement for compliance. Not to mention: when people are unable to opt out, they are far more likely to hit the “Mark as Spam” button instead.

Avoid images, links, and attachments in the first email

Spam filters are highly sensitive to emails that contain media or external links in the first touchpoint. If your first email contains images, links, or attachments, it sends a signal to email providers that your message could be unsafe or promotional. As a result, there’s a significantly higher chance that your email will end up in the spam or junk folder, drastically lowering the chances of your recipient ever seeing it.

Ask for opt-outs

It’s important to give people a way to unsubscribe — but if you can’t include links, you’ve got to find another way to do so. Including a line that asks recipients to respond “remove me” is a good way to cover all of your bases.

Avoid spam words

Spam words are terms or phrases commonly associated with deceptive, misleading, or overly promotional email content. Words like "free," "buy now," "urgent," and "limited time offer" are just a few examples that can make your email look suspicious to both spam filters and recipients.

Don’t send the same message twice

Email providers like Google view identical (or nearly identical) messages as a sign of spammy behavior. When you send the same email repeatedly, you risk your messages being flagged by spam filters, damaging your domain’s reputation and reducing the likelihood that future emails will make it to your recipient’s inbox. Avoid phrases like "thoughts?" or "bump!" in follow-ups. Instead, reframe your follow-up with new context, value, or a specific question that encourages engagement.

Avoid high-volume sends

Email providers like Google have become increasingly sophisticated in identifying and filtering out bulk email campaigns. Bulk emailing can hurt your domain reputation in two ways:

1. By email service providers automatically sending it to spam, OR
2. By getting manually marked as spam by recipients who don’t find the content valuable

Google and other major players associate high-volume sends — especially over 5,000 emails daily — with spammers. Sending too many emails or including too many recipients at once (over 250 per email) increases the likelihood of hitting spam traps, facing bounce-backs, and accumulating complaints.

Avoiding adding the same person to multiple campaigns

Lack of personalization diminishes the recipient's trust in your brand, making it clear they’re just another name on a mass email list. Instead of feeling valued, the recipient might feel spammed, which increases the chances they’ll ignore, unsubscribe from, or mark your emails as spam.

True personalization (aka relevance) is key in recruitment. When a candidate feels like you're sending them generic or mismatched emails, it reflects poorly on your professionalism and reduces their likelihood of engaging with your emails. Candidates want to feel like you're reaching out to them for a specific reason — not just because they were added to multiple campaigns without distinction.

Use ABCD campaigns

The ABCD method is a strategic approach to email outreach where you create multiple variations of your emails to avoid sending the same exact message to all your contacts.

• A: You create four different subject lines.
• B: For each subject line, you write three different versions of the email content.
• C: In total, you’ll have 12 unique combinations of subject lines and email messages.
• D: You send each version to a smaller group of prospects, for example, 8 people per version.

This gives you the ability to send 12 distinct messages instead of one mass email, all while keeping the volume low enough to stay under spam radar.

Diversify your outreach channels

By incorporating channels like social media, phone calls, and even SMS into your outreach strategy, you increase your chances of engagement.

The order and cadence of your outreach plays a critical role in how you’re perceived. You shouldn’t look at multi-channel outreach as a way to “get around” email compliance regulations or to continue engaging in spammy behavior — rather, it’s an opportunity to break through the noise and communicate with candidates in a way that makes sense for them.

Relevance over personalization

While personalization tokens like merge fields were once enough to grab attention, today's recipients are much more discerning. They’ve got dozens of “FIRST NAME, thoughts?” emails in their inboxes. Relevance shows that you’ve done your homework and crafted a message specifically for them, addressing their concerns, roles, or opportunities.

Optimize your campaigns

To maintain strong deliverability and engagement rates, it's essential to regularly review and fine-tune your email campaigns. Optimization starts with tracking and measuring the effectiveness of each campaign.

• Which subject lines had the highest open rates?
• Which email content led to the most replies or conversions?
• What day of the week resulted in the highest engagement?

Once you have this information, you can double down on winning strategies and improve the ones that don’t.