Why are my emails delayed when sent to Gmail and I use a Coherent Path template?
Matthew Whittaker
Co-founder & CTO, Suped
Published 21 Jun 2025
Updated 19 Aug 2025
7 min read
Email delays, especially when sending to a critical recipient like Gmail, can be incredibly frustrating. When you're dealing with delays of 1-4 hours, it's a clear sign that something is amiss, even if your Google Postmaster Tools (GPT) show a healthy reputation and no reported delivery errors. This often points towards a nuanced issue that standard checks might miss.
The suspicion that a new Coherent Path template might be the culprit is a strong lead, as changes in email content can significantly impact deliverability, even with a strong sender reputation. Let's delve into why this might be happening and what steps to take to diagnose and resolve these persistent delays.
Template impact on Gmail delays
When a new template, like one from Coherent Path, is introduced, it can inadvertently trigger email filters. While your domain and IP reputation might be high, Gmail's sophisticated filtering systems also analyze the content of your emails extensively. This analysis happens after the message has been accepted during the DATA phase of the SMTP transaction, meaning the email isn't immediately bounced, but rather held for deeper inspection.
The new template might contain elements that Gmail's algorithms perceive as suspicious. This could include, but is not limited to, overly complex HTML, unusual CSS, excessive links, specific keywords, or even images that are too large or have problematic aspect ratios. These factors can lead to the email being placed in a queue for a more thorough scan, resulting in significant delays before it reaches the recipient's inbox.
It's also worth considering that a template change could alter the ratio of text to images, the number of tracking pixels, or the overall size of the email. Even subtle shifts can have an impact. Understanding why new templates affect deliverability is key to troubleshooting these issues.
Understanding Gmail's filtering mechanisms
Gmail employs a multi-layered filtering process to protect its users from spam and malicious content. While your IP and domain reputation are crucial, they are not the only factors. Content analysis plays a significant role. If the new Coherent Path template uses practices that Google's filters deem unusual or potentially problematic, even if they are not overtly spammy, it can lead to deferred delivery.
These delays aren't necessarily a sign that you're blacklisted (or on a blocklist). They often indicate that your emails are undergoing additional scrutiny, perhaps due to factors like unusual sending patterns, or the detection of suspicious content within the message body. This can be especially true for a new template that hasn't built up a positive sending history with Gmail.
Understanding what causes Gmail delays in this context is vital. It's not just about what you send, but how it's structured and perceived by the recipient's system. Monitoring your Google Postmaster Tools is a good starting point, but deeper content analysis might be required.
Content quality tips
HTML validation: Ensure your new template's HTML is clean and well-formed. Poorly coded HTML can trigger spam filters.
Text to image ratio: Avoid emails that are almost entirely images. A healthy balance of text and images is often preferred.
Link quality: Check all links within the template. Ensure they are legitimate, not shortened, and don't lead to suspicious domains.
Plain text version: Always include a robust plain text version of your email. This fallback is crucial for accessibility and deliverability.
Common causes of email delays
Beyond content, email delays can stem from several technical issues, sometimes originating from your Email Service Provider (ESP) or the receiving server. One common cause is greylisting, where the receiving server temporarily rejects an email from an unfamiliar sender, requesting the sending server to try again later. If the sending server is legitimate, it will retry, and the email will eventually be delivered. This can account for delays of minutes to hours.
Another factor is rate limiting, where an ISP like Gmail will temporarily hold or defer emails if a sender exceeds a certain volume or frequency threshold. This isn't necessarily a punishment but a protective measure against potential spam floods. Your ESP might be encountering this, especially with a new template that could be inadvertently signaling a change in sending patterns. Server congestion or temporary issues at the ESP or Gmail's end can also contribute.
While greylisting is a possibility, it's not always the first conclusion. It's crucial to gather more data before jumping to conclusions, as different deliverability issues can present similar symptoms. Consulting your ESP's SMTP logs for deferrals or soft bounces is a critical next step to pinpoint the exact reason for these delays. You can also learn more about understanding email greylisting.
Content-related delays
Cause: New or altered email templates, problematic HTML/CSS, excessive images, or spammy keywords.
Diagnosis: Email passes initial authentication but is then held by Gmail's content filters.
Solution: A/B test different content variations, simplify template, or revert to an older, successful template.
Server-side or ESP-related delays
Cause: Greylisting, rate limiting by ISPs, network congestion, or ESP's internal queueing.
Diagnosis: Review SMTP logs from your ESP for deferral messages.
Solution: Contact your ESP's support to investigate their queues and connection logs.
Investigating and resolving delays
To accurately diagnose the issue, you need to gather as much data as possible. Request full SMTP logs from your ESP. These logs will show the precise timestamps of when the email was handed off to Gmail's servers and any responses received, including deferral codes. This will tell you if the delay is happening before or after Gmail receives the message.
Another crucial step is to examine the full email headers of a delayed message. Most email clients, including Google, allow you to view the original message with all header information. Pay close attention to the Received headers, which trace the path of the email and indicate where any significant delays occurred. If headers appear incomplete or unusual, that itself can be a red flag.
Once you have the logs and headers, you can start correlating the timestamps. If the delay is consistent and originates from Gmail's side after accepting the message, then the template is the most likely suspect. If the delay occurs before Gmail acknowledges receipt, the issue might be with your ESP's sending infrastructure or queuing. Try sending an email with a proven, old template to see if the delay persists. This can quickly confirm if the new template is indeed the root cause, helping you resolve slow email delivery.
Example of email headers showing a delaytext
Received: from mail.example.com (mail.example.com [192.0.2.1])
by mx.google.com with ESMTPS id abcdefg12345hijk.0.2023.01.01.12.34.56
for <recipient@gmail.com>
(version=TLS1_2 cipher=AEAD_AES_256_GCM_SHA384 bits=256/256)
Wed, 1 Jan 2023 12:34:56 -0800 (PST)
Received: from [10.0.0.1] (localhost [127.0.0.1])
by mail.example.com (Postfix) with ESMTPA id A1B2C3D4E5F6
Wed, 1 Jan 2023 08:30:00 -0800 (PST)
Factor
Impact on deliverability
Common cause of delay
Content quality
Can trigger spam filters, leading to deeper inspection queues.
Ensure your new email templates are thoroughly tested across various email clients and ISPs.
Maintain a balanced text-to-image ratio within your email content.
Regularly monitor your email sending logs for any deferrals or error messages.
Verify all links in your templates lead to reputable and secure destinations.
Always provide a valid and well-formatted plain text version of your emails.
Common pitfalls
Ignoring SMTP logs and not verifying for soft bounces or deferrals.
Assuming good sender reputation covers all deliverability issues.
Not testing new templates extensively before full deployment.
Overlooking hidden tracking pixels or excessive embedded code.
Failing to review full email headers for critical delay timestamps.
Expert tips
If using a third-party template, check if they adhere to the latest email coding standards.
Implement A/B testing for new templates to identify any performance differences.
Utilize Google Postmaster Tools for detailed insights into your Gmail deliverability.
Segment your audience when testing new templates to minimize overall impact.
Consult with your ESP's deliverability experts for deeper analysis of complex issues.
Marketer view
A marketer from Email Geeks says they started seeing major delays at Gmail, ranging from 1 to 4 hours, shortly after implementing a new template from Coherent Path. Despite Google Postmaster Tools showing high IP and domain reputation, and no reported bounce rates, they were still experiencing issues and were waiting for SMTP logs from their ESP.
2023-04-27 - Email Geeks
Expert view
An expert from Email Geeks says Google is likely not intentionally holding onto messages internally. It's possible Gmail dislikes the new template, leading to delays after the DATA command, or there's an issue within the ESP causing a significant delay between the MTA receiving the message and Google receiving it.
2023-04-27 - Email Geeks
Diagnosing and resolving email delays
Email delays to Gmail, particularly when tied to a new template, often highlight the intricate relationship between content, infrastructure, and recipient filtering. While a good sender reputation is foundational, it doesn't exempt emails from content-based scrutiny or server-side throttling. The key to resolving these issues lies in a methodical approach to data collection and analysis.
By examining SMTP logs for deferrals and analyzing full email headers for timestamps, you can pinpoint where the delays are occurring. Testing with a different template will quickly confirm if the Coherent Path template is indeed the source of the problem. This focused investigation will guide you towards the necessary adjustments, whether it's refining your template's code or working with your ESP to optimize sending parameters.
Gmail's content filters.
Google, allow you to view the original message with all header information. Pay close attention to the Received headers, which trace the path of the email and indicate where any significant delays occurred. If headers appear incomplete or unusual, that itself can be a red flag.
