# Since updating to 2021-04-09 Experimental (on Linux) get non-blocking socket error
**URL:** https://forum.duplicati.com/t/since-updating-to-2021-04-09-experimental-on-linux-get-non-blocking-socket-error/12232
**Category:** Support
**Created:** [April 22, 2021, 10:29pm UTC](https://forum.duplicati.com/t/since-updating-to-2021-04-09-experimental-on-linux-get-non-blocking-socket-error/12232 "2021-04-22T22:29:13Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@tringoldsby](https://forum.duplicati.com/u/tringoldsby)
#### Post date: [April 22, 2021, 10:29pm UTC](https://forum.duplicati.com/t/since-updating-to-2021-04-09-experimental-on-linux-get-non-blocking-socket-error/12232/1 "2021-04-22T22:29:13Z")
Since updating a Duplicati instance on a Linux system to the 2021-04-09 Experimental release I get the following error message every time a backup runs.
2021-04-22 02:18:06 -06 - [Warning-Duplicati.Library.Modules.Builtin.ReportHelper-ReportSubmitError]: Failed to send message: System.IO.IOException: Operation on non-blocking socket would block → System.Net.Sockets.SocketException: Operation on non-blocking socket would block
The backup seems to complete fine - just the puzzling error message.
---
### Author:  [@tringoldsby](https://forum.duplicati.com/u/tringoldsby)
#### Post date: [April 22, 2021, 10:32pm UTC](https://forum.duplicati.com/t/since-updating-to-2021-04-09-experimental-on-linux-get-non-blocking-socket-error/12232/2 "2021-04-22T22:32:04Z")
Further testing suggests that it may be related to the option to send a mail message after backup. If so, this may be related to an issue reported by another user in December 2020
> [@Sendmail exception "Operation on non-blocking socket would block"](https://forum.duplicati.com/t/sendmail-exception-operation-on-non-blocking-socket-would-block/11364):
>
> Hi, Duplicati 2.0.5.1\_beta\_2020-01-18 on macOS 10.13 Sendmail config: { "Filter": "", "Name": "--send-mail-url", "Value": "smtp://smtp.mail.ru:465/?starttls=when-available", "Argument": null }, { "Filter": "", "Name": "--send-mail-username", "Value": "\@mail.ru", "Argument": null }, { "Filter": "", "Name": "--send-mail-password", "Value": "\", "Argument": n…
---
### Author:  [@tringoldsby](https://forum.duplicati.com/u/tringoldsby)
#### Post date: [April 23, 2021, 12:55am UTC](https://forum.duplicati.com/t/since-updating-to-2021-04-09-experimental-on-linux-get-non-blocking-socket-error/12232/3 "2021-04-23T00:55:59Z")
And indeed - disabling the mail alert cures the problem.
---
### Author:  [@ts678](https://forum.duplicati.com/u/ts678)
#### Post date: [April 24, 2021, 7:51pm UTC](https://forum.duplicati.com/t/since-updating-to-2021-04-09-experimental-on-linux-get-non-blocking-socket-error/12232/4 "2021-04-24T19:51:03Z")
> [@tringoldsby](#):
>
> disabling the mail alert cures the problem.
The forum topic you cited fixed their email through options changes, if you wish to pursue that sometime.