1 Topic by snowc

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Topic: SENT_SECOND_EHLO when setting send from email option in Gmail

==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release): 1.7.4 MARIADB edition.
- Deployed with iRedMail Easy or the downloadable installer? Downloadable
- Linux/BSD distribution name and version: Ubuntu 24.04 Noble Numbat arm64
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MySQL
- Web server (Apache or Nginx): Apache
- Manage mail accounts with iRedAdmin-Pro? No
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====
All,
I am experiencing an error when attempting to send email from my main gmail address.
I am using Gmail to add my brycemonaghan.qzz.io email into the stormsnsnow@gmail.com account in order to send mail as brycemonaghan.qzz.io. The following message is below
Authentication error. Check your username and password.
Server returned error: "The outbound connection was established to the relay brycemonaghan.qzz.io [REDACTED], but was unable to complete the message transaction, either because of time-out, or inadequate connection quality. For more information, go to - Missed upload deadline (state SENT_SECOND_EHLO), code: 421"
The logs are posted above for your reference, as I cannot attach the mail.log as it is too large.
The selected file was too large to upload. The server didn't allow the upload.
Thanks
snowc

----

Spider Email Archiver: On-Premises, lightweight email archiving software developed by iRedMail team. Supports Amazon S3 compatible storage and custom branding.

2 Reply by anparrish

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Re: SENT_SECOND_EHLO when setting send from email option in Gmail

Code 421 with SENT_SECOND_EHLO often points to a timeout or connection issue after the initial handshake, not just wrong credentials. Have you checked firewall rules, reverse DNS and whether Gmail IPs are being rate limited or blocked on your server?

3 Reply by ZhangHuangbin

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Re: SENT_SECOND_EHLO when setting send from email option in Gmail

snowc wrote:

The logs are posted above for your reference, as I cannot attach the mail.log as it is too large.
The selected file was too large to upload.

Please extract Postfix log lines related to your testing email, do not upload full log file.

4 Reply by snowc (edited by snowc 2026-02-25 22:16:58)

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Re: SENT_SECOND_EHLO when setting send from email option in Gmail

ZhangHuangbin wrote:
snowc wrote:

The logs are posted above for your reference, as I cannot attach the mail.log as it is too large.
The selected file was too large to upload.

Please extract Postfix log lines related to your testing email, do not upload full log file.

Here you go

Post's attachments

2026-02-15T005520.921069-0500 bryce.txt 5.34 kb, 1 downloads since 2026-02-25 

You don't have the permssions to download the attachments of this post.

5 Reply by snowc

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Re: SENT_SECOND_EHLO when setting send from email option in Gmail

anparrish wrote:

Code 421 with SENT_SECOND_EHLO often points to a timeout or connection issue after the initial handshake, not just wrong credentials. Have you checked firewall rules, reverse DNS and whether Gmail IPs are being rate limited or blocked on your server?

I already checked, and its whitelisted. Also, its the right credentials. UFW is allowed on all ports (25, 110, 993, 995, 143, 587, 465)

6 Reply by ZhangHuangbin

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Re: SENT_SECOND_EHLO when setting send from email option in Gmail

snowc wrote:

Here you go

I don't see any log lines with smtp code "421" as mentioned in your first post.

7 Reply by snowc

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Re: SENT_SECOND_EHLO when setting send from email option in Gmail

ZhangHuangbin wrote:
snowc wrote:

Here you go

I don't see any log lines with smtp code "421" as mentioned in your first post.

It's in Gmail. I tried doing send mail as and it wont work. Incoming mail is fine. Outgoing is not.

8 Reply by ZhangHuangbin

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Re: SENT_SECOND_EHLO when setting send from email option in Gmail

What are the Postfix log lines related to the outgoing?