Important notice: SMTP by Zapier tool to discontinue port 25

Written by Owner

Updated at August 20th, 2025

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Action required: Why are we making this change? Need help?

Note

This information was accurate at the time of publication. Please check out the latest product update notes for any updates or changes.

To enhance security, reliability, and performance, we’re deprecating SMTP by Zapier app connections using port 25 starting February 17, 2025.

To avoid disruptions to your workflows:

Update any Zaps that use SMTP:
- Reconnect your app connections that currently use port 25.
- Zapier recommends port 587, the industry standard for secure email delivery.
Test your updated workflows: Ensure all emails are being sent as expected after the port change.

Enhancing the SMTP tool: These improvements align the SMTP tool with the Zapier Platform V3 standards, which do not support port 25 within AWS Lambdas.
Discontinuing port 25:
- Port 25 is frequently blocked by internet service providers (ISPs).
- It lacks support for modern security protocols like encryption.
- It is primarily designed for server-to-server communication, making it unsuitable for client email submissions.

You can reach out to Zapier Support if you have questions or need help.

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