Why is only one sales rep's email being blocked when others aren't?

One sales rep's emails might be blocked while others aren't due to a combination of factors. This can include a difference in their individual sender reputation, specific content or URLs they are using (even if subtle), the particular email list they are sending to (e.g., if it contains more spam traps or invalid addresses), or if specific recipients or their email security systems (like Mimecast ) have specifically blocklisted them.

How can I identify the specific reason for email blocking?

Start by analyzing the bounce messages or error codes received when the emails are blocked (e.g., SMTP 550 or 554 errors). These often provide clues. Then, compare the blocked rep's email content, sending volume, and recipient list against those of successful reps to identify any unique patterns or elements. Checking your overall domain and IP reputation using tools like blocklist checkers can also help rule out broader issues.

What steps should I take to improve a sales rep's email deliverability?

To improve the rep's deliverability, ensure they are sending to highly engaged and verified email lists. Review and refine their email content to remove any spam trigger words or suspicious links. Implement a gradual sending ramp-up if they are new or have increased volume. Encourage recipients to whitelist the rep's email address and always honor unsubscribe requests promptly.

Does using Gmail as a sender impact deliverability for sales emails?

Yes, using Gmail for high-volume sales outreach can impact deliverability. While Gmail itself has a strong reputation, individual Gmail accounts operate within a shared IP infrastructure. If one user on a shared IP engages in behavior that leads to spam complaints or low engagement, it can affect the reputation of other senders on the same IP. Additionally, high volumes from a personal Gmail account may be seen as unusual for typical user behavior, flagging automated systems.

Why is one sales rep's email blocked when others aren't? - Troubleshooting - Email deliverability - Knowledge base

It can be incredibly frustrating when you have a sales team, and suddenly, one rep's emails start getting blocked while everyone else's are landing in inboxes just fine. I've heard this scenario described countless times, and it's always a head-scratcher. You might assume everyone is following the same processes and using similar messaging, so why the disparity?

This isn't just a random occurrence. It points to underlying issues that are often nuanced and specific to the individual sender, their sending patterns, or how their messages are perceived by recipients and their email systems. Understanding these factors is crucial for diagnosing the problem and getting that sales rep's emails back on track.

We'll explore the common reasons why one sales rep's emails might face blocking or blacklisting issues, even when their colleagues are successfully reaching the inbox. From individual sender reputation to content variations and recipient-side filtering, there are many layers to uncover.

The individual sender's impact

Every email sender builds a reputation over time, and this applies to individual email addresses just as much as it does to domains or IP addresses. Even if your company's overall domain reputation is solid, a specific sales rep's sending habits can negatively impact their personal sender reputation.

Consider the volume and consistency of their outreach. If one rep suddenly ramps up their sending volume significantly or sends emails to a high percentage of invalid or unengaged addresses, it can raise red flags for internet service providers (ISPs) and spam filters. Similarly, if they are receiving a higher number of spam complaints compared to their peers, this directly damages their individual standing.

Content also plays a critical role. While you might think all sales reps use similar templates, even minor variations can trigger filters. This includes specific words, phrases, link structures, or image-to-text ratios. One rep might inadvertently include elements that others avoid, leading to their emails being flagged.

Engagement metrics: A rep with low open rates, high bounce rates, or more spam complaints will see worse deliverability, regardless of domain.
Content variations: Even subtle differences in subject lines, body text, link shorteners, or signature lines can be detected by filters as potentially spammy content.
List quality: If the rep is using a slightly different or older list, it might contain more invalid addresses or spam traps, immediately leading to blocks.

Technical configurations and shared infrastructure

While individual sender reputation is important, the underlying technical configuration of email sending can also play a role. Most businesses use shared IP addresses provided by their email service provider, even for services like

Gmail. This means the behavior of other senders on the same IP can affect yours. However, if only one rep is blocked, it's less likely a global IP issue and more likely something specific to their sending.

Check email authentication. While generally set at the domain level, misconfigurations or subtle differences in how a specific rep's emails are routed or sent could theoretically lead to issues. This includes ensuring correct SPF,

DKIM, and DMARC records are in place and consistently applied.

Individual reputation

Each sales rep builds their own sender reputation based on their specific sending behavior. This reputation is tied to their individual email address and can be impacted by their unique sending patterns, content, and recipient engagement. If one rep is generating more spam complaints or hitting more invalid addresses, their individual reputation will suffer.

While less common for individual reps using standard email clients, a compromised account could also be a factor. If the rep's account has been accessed by an unauthorized third party, it could be used for spamming, leading to their emails being blocklisted or flagged. Regular security checks and strong passwords are always advisable.

Recipient-side filtering and policies

Often, the problem isn't with your sending, but with the recipient's filtering systems. Many organizations use robust email security solutions like Mimecast or Proofpoint that employ strict security policies. These policies can block emails based on content, sender reputation, or even specific URLs embedded in the message.

A common scenario involves SMTP error codes like 550 or 554, which often indicate that the recipient's mail platform has actively decided to block the email. This decision can be triggered by a security rule, an irritated mail administrator, or even a previous spam report from within that organization.

If a rep's email content, even if seemingly harmless, contains a specific URL that an organization has blocklisted, or if a particular recipient has manually added the sender to their personal blocklist, the emails will be rejected. This explains why other reps, sending similar but not identical emails, might bypass these filters.

Proactive steps

Check bounces: Analyze bounce messages for specific error codes or explanations from recipient servers. This is often the first clue.
Review content: Compare the exact email content, including signatures and links, between the blocked rep and successful reps. Look for any unique elements.

Reactive measures

Segment audiences: Temporarily reduce sending to any domains where blocks are frequent for that specific rep.
Warm up: If the rep is new or has increased volume, gradually warm up their sending by starting with smaller, highly engaged lists before expanding.

Finally, the human element cannot be overlooked. If a particular rep has a history of aggressive or persistent outreach to certain recipients or organizations, those recipients might mark their emails as spam more often, or even contact their IT department to specifically block that sender's email address. Once blocked, even future legitimate emails from that rep may not get through, whereas another rep contacting the same organization for the first time might bypass the block (unless the entire domain is blocklisted).

Finding the root cause

When one sales rep's emails are blocked while others aren't, it's rarely a simple issue. It points to a combination of factors related to individual sending behavior, subtle content differences, and how receiving servers, like those using Mimecast, interpret incoming messages. It's a clear signal that something unique about that specific sender's email stream or target audience is triggering spam filters or security rules.

The key to resolving this lies in a detailed investigation. Start by analyzing bounce messages to understand the specific error codes. Then, meticulously compare the blocked rep's email content, sending volume, and recipient lists against those of the successful reps. Look for any discrepancies, no matter how small.

By pinpointing the exact triggers, you can implement targeted solutions, whether that involves adjusting email content, refining audience targeting, improving list hygiene, or even retraining the sales rep on best practices for outreach. Proactive monitoring and a data-driven approach are essential to maintaining strong email deliverability across your entire team.

Views from the trenches

Best practices

Always maintain a clean email list by regularly removing inactive or bounced addresses to prevent deliverability issues.

Personalize emails as much as possible to avoid generic content that often triggers spam filters and reduce bounce backs.

Monitor individual rep sending volumes and complaint rates to identify potential problems before they escalate.

Educate sales reps on email best practices, including avoiding spam trigger words and excessive links.

Implement email authentication standards like SPF, DKIM, and DMARC to build sender trust and improve deliverability.

Common pitfalls

Sending to purchased or old email lists that contain a high number of invalid addresses or spam traps.

Using generic, templated messages with little to no personalization, which is often flagged by recipients as spam.

Ignoring bounce messages and deliverability reports, missing critical insights into why emails are blocked.

Over-sending from a new or cold email account, leading to immediate reputation damage and blocks.

Embedding suspicious or frequently blocklisted URLs or attachments in sales emails.

Expert tips

Verify all email addresses before sending campaigns to minimize bounces and protect sender reputation.

Consider segmenting your email lists based on engagement to avoid sending to unengaged recipients.

A/B test different email contents and subject lines to see what performs best and avoids spam filters.

Use a dedicated sending domain for sales outreach to isolate any deliverability issues from your main domain.

Regularly check major blocklists (or blacklists) to ensure your domain or IP is not listed.

Marketer view

Marketer from Email Geeks says many sales emails are marked as spam because recipients simply do not want to receive them, indicating the email client is functioning correctly by blocking unwanted messages.

2023-11-05 - Email Geeks

Expert view

Expert from Email Geeks says recipients, not senders, determine if an email is spammy, highlighting that the email client is correctly doing its job when it blocks a message based on recipient feedback.

2023-11-05 - Email Geeks