# Incoming mail sent from Fastmail rejected, from Gmail accepted

**URL:** https://meta.discourse.org/t/incoming-mail-sent-from-fastmail-rejected-from-gmail-accepted/296227
**Category:** Support
**Tags:** email
**Created:** [February 21, 2024, 7:46pm UTC](https://meta.discourse.org/t/incoming-mail-sent-from-fastmail-rejected-from-gmail-accepted/296227 "2024-02-21T19:46:15Z")
**Posts on this page:** 1
**Page:** 1

<div class="post-metadata">

### Author: ![jimkleiber](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/jimkleiber/32/121814_2.png) [@jimkleiber](https://meta.discourse.org/u/jimkleiber)
#### Post date: [February 21, 2024, 7:46pm UTC](https://meta.discourse.org/t/incoming-mail-sent-from-fastmail-rejected-from-gmail-accepted/296227/1 "2024-02-21T19:46:15Z")

</div>

For some reason, when I test my incoming mail-receiver from various Fastmail email addresses, the email doesn’t arrive in my Admin \> Emails \> Received or Rejected parts and Fastmail sends me an email with an error saying `Undelivered Mail Returned to Sender` with

```plaintext
    mailuser.nyi.internal[/var/run/lmtpforward/outgoing] said: 550 5.1.1
    <info@forum.myforum.com>: Recipient address rejected: User unknown in
    virtual mailbox table via compute4 (in reply to end of DATA command)

```

But when I send with one of my various Gmail addresses, the email arrives to the site into Admin \> Emails \> Received.

Any idea why Fastmail might be failing?