Summary
The overwhelming consensus from experts, marketers, and email deliverability documentation is that including an email address in the subject line is a poor practice. It's often associated with spam, can trigger spam filters, reduces open rates, and appears impersonal. Personalized subject lines using the recipient's name or relevant content are highly recommended as a more effective alternative.
Key findings
- Spam Association: Using an email address in the subject line is frequently associated with spam, making emails look less legitimate.
- Spam Filter Trigger: Email addresses, especially from untrusted sources, can trigger spam filters and negatively impact deliverability.
- Reduced Open Rates: Subject lines with email addresses are likely to experience reduced open rates compared to personalized subject lines.
- Personalization is Key: Personalizing subject lines with the recipient's name or relevant information significantly improves engagement and deliverability.
Key considerations
- Sender Reputation Matters: A strong sender reputation can help mitigate the negative impact of using an email address, but it's still not recommended.
- Alternative Identification Methods: Consider using first and last names or other relevant details instead of email addresses for identification or personalization purposes.
- Relevance and Value: Focus on crafting subject lines that are relevant, engaging, and provide value to the recipient to encourage opens.
- Compliance with Regulations: Be aware of regulations like CASL that require full disclosure and may impact the use of personal information in subject lines.
- Testing for Impact: If there's a specific need to use an email address in the subject line, A/B testing should be conducted to evaluate its impact on deliverability and engagement.
What email marketers say
8 marketer opinions
The consensus among email marketers is that including an email address in the subject line is generally a bad practice. It can trigger spam filters, appear impersonal or spammy, and reduce open rates. Personalization with the recipient's name or other relevant information is a much more effective strategy.
Key opinions
- Spam Trigger: Using email addresses in the subject line can cause emails to be marked as spam by email providers like Gmail.
- Reduces Open Rates: Subject lines with email addresses are likely to reduce email open rates due to looking spammy or impersonal.
- Personalization Alternative: Personalizing subject lines with the recipient's name or other relevant information is more effective than using an email address.
Key considerations
- Sender Reputation: Consider the sender's reputation, as this can influence whether including an email address in the subject line triggers spam filters.
- Personalization Opportunities: Explore opportunities for personalization beyond using email addresses, such as using names or other relevant details.
- Testing: A/B testing can be conducted to evaluate the impact of using email addresses in subject lines versus other approaches.
Marketer view
Email marketer from Mailchimp Resource shares that while there are no hard and fast rules, using email addresses in subject lines can be risky. They recommend focusing on clarity, brevity, and personalization to increase open rates and avoid spam filters.
1 Dec 2024 - Mailchimp Resource
Marketer view
Email marketer from Email on Acid states that email subject lines should be carefully crafted to avoid being marked as spam. It says that it is not a good practice to include an email address in the subject line.
1 Jul 2024 - Email on Acid
What the experts say
4 expert opinions
Experts generally advise against using email addresses in subject lines. Using a person's name is considered more legitimate and less spammy. Subject lines should be relevant and avoid spam triggers. Testing is suggested if an email address must be used.
Key opinions
- Spam Appearance: Using email addresses in subject lines can make emails appear spammy.
- Legitimacy: Using a person's name is considered more legitimate than using an email address in the subject line.
- CASL Compliance: CASL requires full disclosure of the "friend" sending the message, which can be accomplished by using a full name.
- Spam Triggering: Email addresses may trigger spam filters, depending on the context and sender reputation.
Key considerations
- Testing: If an email address must be used in the subject line, A/B testing is recommended.
- Sender Reputation: The sender's reputation influences whether including an email address triggers spam filters.
- Alternative Approaches: Consider using first and last names instead of email addresses for identification purposes.
Expert view
Expert from Email Geeks says that aside from people giving fake addresses in forms, putting an email address in the subject line might look spammy but suggests testing it.
18 Nov 2024 - Email Geeks
Expert view
Expert from Email Geeks suggests using first and last name instead of an email address in the subject line, mentioning that not everyone knows people by their email address and that CASL requires full disclosure of the "friend" sending the message.
30 Sep 2021 - Email Geeks
What the documentation says
5 technical articles
Email deliverability documentation consistently advises against including email addresses in subject lines. This is primarily due to the association with spam tactics and the potential to trigger spam filters. Best practices emphasize concise, engaging subject lines that avoid suspicious content.
Key findings
- Spam Tactic: Using email addresses in the subject line is a common tactic used by spammers.
- Spam Filter Trigger: Email addresses and URLs from untrusted sources in the subject line increase the likelihood of emails being marked as spam.
- Deliverability Impact: Including email addresses negatively impacts email deliverability.
- Relevance & Engagement: Concise and engaging subject lines are preferred, implying that including an email address detracts from this.
Key considerations
- Sender Reputation: Ensure a good sender reputation and proper authentication to mitigate the risk of emails being marked as spam.
- Subject Line Content: Avoid suspicious subject line content to prevent triggering spam filters.
- Alternative Approaches: Focus on creating concise, engaging subject lines that offer value to the recipient instead of including email addresses.
Technical article
Documentation from Sendgrid explains that email deliverability is key, and the email subject line is one of the most important components. They state that the best approach is to avoid using any email address.
6 Jan 2024 - Sendgrid
Technical article
Documentation from Microsoft Support explains that including email addresses or URLs from untrusted sources in the subject line can increase the likelihood of emails being marked as spam. They suggest ensuring sender reputation and proper authentication to improve deliverability.
7 Nov 2024 - Microsoft Support
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