How does a P.S. at the end of a personalized email affect deliverability and engagement?
Matthew Whittaker
Co-founder & CTO, Suped
Published 18 Jun 2025
Updated 18 Aug 2025
6 min read
The use of a P.S. (postscript) at the end of an email is a classic technique, often associated with a more personal, one-to-one communication style. While it's widely believed to enhance engagement, the question of its direct impact on email deliverability is often debated.
Many email marketers and deliverability experts intuitively feel that a P.S. is a net positive, especially in highly personalized messages. It can add a human touch, highlight a key call to action, or even serve as a last-minute thought. The challenge often lies in finding concrete data to support these intuitions, particularly when dealing with smaller send volumes where A/B testing can be difficult to yield statistically significant results.
I've explored this topic and gathered insights to shed light on how a P.S. can influence both how your emails land in the inbox and how recipients interact with them. Ultimately, the effect of a P.S. isn't always straightforward.
Direct impact on deliverability
When we talk about email deliverability, we're primarily concerned with whether an email successfully reaches the recipient's inbox, rather than being shunted to the spam folder or blocked entirely. Content within the email body, including a P.S., generally has a negligible direct impact on this initial inbox placement.
Spam filters and inbox providers like Google and Microsoft primarily evaluate sender reputation, authentication (like DMARC, SPF, and DKIM), and the overall context of the sending patterns. A simple P.S. at the end of a message is usually just considered another piece of text within the email content. It's not inherently a spam trigger word unless it's abused with problematic keywords or links typically associated with unsolicited bulk email.
The physical placement of the P.S. within the email body also has no direct bearing on how spam filters assess the message. Filters analyze the entire content for patterns, not necessarily the specific line where certain phrases appear. Therefore, you don't need to worry that simply adding P.S. will cause your emails to land in the junk folder.
Engagement vs. deliverability
While a P.S. may not directly impact whether your email makes it to the inbox, its influence on engagement is where its true power lies. Email engagement refers to how recipients interact with your emails, including opens, clicks, replies, and even deletions or marking as spam.
A P.S. is often one of the most-read parts of an email, second only to the subject line. This makes it an ideal spot to reinforce your main message, add a compelling call to action, or inject a touch of personality. If the P.S. is enticing and relevant, it can significantly boost engagement metrics like click-through rates and replies. Positive engagement signals to inbox providers that your emails are valued by recipients, which in turn can positively influence your sender reputation over time.
Conversely, if a P.S. is irrelevant, misleading, or contains content that irritates the recipient, it could lead to negative engagement. This might include recipients marking your email as spam, deleting it without reading, or even unsubscribing. These negative signals can degrade your sender reputation and indirectly hurt your deliverability. For example, some users might mark an email as spam if the P.S. feels too gimmicky or irrelevant, even if it isn't technically spam.
Positive engagement
Increased opens: While the P.S. is seen after opening, its potential to reinforce the message can encourage future opens.
To leverage a P.S. effectively, consider its content and purpose carefully. The goal is to enhance the recipient's experience and encourage a desired action, not to confuse or annoy them. A well-crafted P.S. should feel like a natural extension of your personalized message.
When incorporating a P.S. into your emails, think about how it complements your overall email marketing strategy. Is it reinforcing a limited-time offer, a valuable resource, or a simple human connection? The more relevant and timely the P.S. is, the better its chances of driving positive engagement.
It's also important to remember that while a P.S. can be powerful, it's just one element of your email. Overall email content quality, list hygiene, and proper authentication remain paramount for strong deliverability. A good P.S. can amplify a good email, but it won't save a bad one.
Effective P.S. content
Call to action: Reinforce the main CTA or provide an alternative, less-pressuring one.
Personal touch: Add a genuine, friendly, or slightly informal note.
Urgency/Scarcity: Briefly mention a deadline or limited availability.
Bonus content: Offer an unexpected tip, resource, or discount.
Using a P.S. as a subtle way to encourage replies or foster a connection, especially for niche brands, can be incredibly effective.
P.S. pitfalls to avoid
Overuse of keywords: Stuffing the P.S. with salesy or spammy phrases.
Irrelevant content: Including information that doesn't align with the main email message.
Too many links: Overloading the P.S. with multiple clickable elements can look suspicious.
Lack of personalization: A generic P.S. in a supposedly personalized email feels off.
While a P.S. usually won't directly hurt deliverability, poor content can lead to negative user reactions, increasing the risk of being blacklisted or blocklisted due to spam complaints.
Testing and measuring impact
To truly understand the impact of a P.S. in your specific context, especially concerning engagement, testing is invaluable. While direct deliverability might not be affected, the nuances of your audience's reaction to different P.S. styles can vary greatly.
Consider setting up A/B tests (or A/B/C tests) where one version of your email includes a P.S. and another does not, or where different P.S. messages are used. Monitor key engagement metrics, such as click-through rates, reply rates, and conversion rates. This data will provide clear insights into what resonates with your audience and what doesn't.
Also, pay attention to the qualitative feedback, if any. Do recipients mention the P.S. in their replies? Does it seem to influence their perception of your email or brand? This anecdotal evidence, combined with quantitative data, can paint a comprehensive picture of the P.S.'s effectiveness.
Increased reply rates, fosters direct communication
Positive due to explicit engagement signals
P.S. with irrelevant content
Lower engagement, potential for confusion
Neutral to negative if it leads to spam complaints
Views from the trenches
Best practices
Always keep the P.S. concise and impactful, focusing on a single, clear message or call to action.
Ensure the P.S. content is relevant and aligns with the main theme of your personalized email.
Use the P.S. to add a human element, a unique insight, or a slight personal touch that reinforces your brand's voice.
Experiment with different P.S. messages to see what resonates best with your specific audience segments.
Common pitfalls
Avoid using the P.S. as a place to stuff keywords or introduce salesy language, as this can detract from its personal feel.
Don't include too many links or complex information in the P.S., keeping it simple and easy to digest.
Relying solely on a P.S. to boost engagement without ensuring the entire email content is high quality and relevant.
Forgetting to align your P.S. with the level of personalization in the rest of your email, making it feel generic.
Expert tips
A P.S. is often the first thing people read after the subject line. Treat it as a prime piece of real estate.
Consider using a P.S. to gently ask for a reply, which can significantly boost positive engagement signals for deliverability.
The effectiveness of a P.S. is heavily dependent on context, audience, and the overall sending strategy.
Don't be afraid to be a little informal or even playful in your P.S., especially in a highly personalized email.
Expert view
Expert from Email Geeks says that test conditions vary, so relying on someone else's P.S. experiment might not be relevant for your specific needs.
2024-08-05 - Email Geeks
Marketer view
Marketer from Email Geeks says that a P.S. would likely have zero impact on deliverability because it is just more text, and spam filters focus on broader patterns.
2024-08-06 - Email Geeks
The strategic use of a P.S.
The P.S. in a personalized email doesn't directly affect deliverability. Its primary influence is on engagement, which can then indirectly impact your sender reputation and future inbox placement. If a P.S. encourages positive interactions, like clicks or replies, it signals to inbox providers that your emails are relevant and wanted, ultimately improving your overall email deliverability performance.
However, if the P.S. is poorly executed or contains spammy content, it could lead to negative engagement, such as spam complaints, which can harm your deliverability. The key is to treat the P.S. as a valuable part of your communication, using it strategically to enhance the recipient's experience and encourage meaningful interaction.
Ultimately, the decision to include a P.S. should be based on your content strategy and a clear understanding of your audience. When used thoughtfully, a P.S. can be a powerful tool for boosting engagement and reinforcing your message.
Microsoft primarily evaluate sender reputation, authentication (like DMARC, SPF, and DKIM), and the overall context of the sending patterns. A simple P.S. at the end of a message is usually just considered another piece of text within the email content. It's not inherently a spam trigger word unless it's abused with problematic keywords or links typically associated with unsolicited bulk email.
