SMTP-Server Timeout Sending E-Mails & Imap Connection Error or Bug

[a paridae]

Hi, I have the problem that I can not send emails when Avast protection is enabled. Also, there is a problem when using Imap, so email drafts are not saved either or getting E-Mails does not work. I was able to specify the problem in more detail. I herefor ask Avast to solve the problem. Thanks

Basic setup
- New installation of Windows 10 22h2
- Thunderbird version 68 or 115 (latest).
- All email inboxes Yahoo & Google, makes no difference.

On my other computer with the same settings, same Windows 10 Installment, the "Send Email" function works and I get no error messages & sending works.

Error Text in Thunderbird:
Message could not be sent.
The message could not be sent because the connection to the SMTP server smtp.mail.yahoo.com failed. The server is either unavailable or refuses SMTP connections. Please check the SMTP server settings and try again.
Or:
Sending the message failed.
The message could not be sent because the connection to the SMTP server smtp.mail.yahoo.com exceeded its expiration time (timeout). Try again.

Same Error with gmail Mails.

Tests & Trials:
- already fresh Windows 10 Pro installment
- Reinstall Avast, deleting all Appdata stuff and registry cleaning with Glary Utilities
- Turn off all Avast modules 10 minutes, email sending no problem.
- Geek:Area settings are exactly the same on both of my computers (default)
- Geek:Area certificate is already installed says Thunderbird v. 68 & 115 too
- Thunderbird account settings are identical on my machines (mails, ports, imap etc.). Thunderbird Version does not matter.
- Solution: Disable "Scan Outbound Mails (SMTP" does not solve the problem!!
- Testing: The problem already occurs when Avast E-Mail Protection is enabled in Avast Settings (Menu - Settings - Protection -> Core Shields -> Enable Mail Shield [Block Attachments]), the rest was unchecked by myself!

I thank you already for feedback to solve this.
Regards

[HK]

Hi,

I'm very sorry you are having issues with using thunderbird together with avast.

I just tried to send email and message was sent/delivered without any issues.
- Avast 23.10 latest beta
- Thunderbird 115
- Gmail and Yahoo mail

Could you please help us with the investigation by providing some data?

Please enable debug logging (Menu > Settings > General > Troubleshooting > Enable debug logging)
Reproduce the issue (try to send email).

Create a support package (https://support.avast.com/en-eu/article/Submit-support-file) and post the ID here.

Thank you very much,
HK

[a paridae]

Thanks HK for the answering! 

So, I have reactivated Email Protection in Avast settings. I also disabled/enabled/disabled the "Enable Mail Shield [Block Attachments]" setting for 10 minutes while I was doing email sending tests between Yahoo/Gmail addresses, which I own.

Without "Enable Mail Shield [Block Attachments]" E-Mail goes through normal
With enabled Mail Shield [Block Attachments] I get Timeouts, so E-Mails does not go any/all time in my tests

- Avast current updated, enabled debu logging (silent mode does not matter)
- Thunderbird 115.3.1
- NordVPN with connection on/off (doesn't matter) -> Tested this because Custom DNS on/off -> This Custom DNS is only Quad9 9.9.9.9 -> NordVPN is not the cause of the error, which I briefly suspected during my tests.

File ID: ZUZSS
Ticket number: 911911911911911

Thanks

[HK]

Thank you. Regrettably, this file was not delivered to our FTP for some reason. Could you please upload it manually? The steps are described here: https://support.avast.com/en-ww/article/160/
The ZIP file with logs is in the following directory: C:\Users\%username%\AppData\Local\AvastSupport\
To access this directory, you can press Win+R, paste %LocalAppData%\AvastSupport and press Enter.

[a paridae]

Hi, I uploaded the files according to the manual. File is called AS20231005_1714_ZUZSS_4249341792.zip.

[Nunzio77]

Read here:

https://forum.avast.com/?topic=325003.new;topicseen#new

[a paridae]

I do have ver. 23.9.6082 - build 23.9.8494.796.
And as I wrote "Scan inbound emails (POP3, IMAP4)" and "Scan outbound emails (SMTP)" was not the problem.
The setting "Enable Mail Shield [Block Attachments]" was noticeable with my Timeout problem.

[HK]

Thanks for the uploading!

Do you happen to have another application installed that could block traffic? Mail.log from support package says that connection to SMTP server time-outed, that means another app blocked the connection. It could be FW or any other security app.

Best regards,
HK

[a paridae]

No I don't have other antivir, even not win defender.

Problem still exists sometimes. I experienced that NordVPN connection is also a part of the problem. Else also without NordVPN the Problem has occured.
Also, on my second PC (Laptop) all was working with same avast & nordvpn connection.

So as I said before.
The Avast tick at E-Mail Protection is causing my problem with the smtp timeout, with or without NordVPN connection.

[a paridae]

What do you mean with FW?

[DavidR]

What do you mean with FW?

FireWall

[a paridae]

Thanks. I just have Windows Firewall.

[DavidR]

Hopefully HK Avast Team can get back to the topic.

[RedFan]

This is a problem going for years , it never gets fixed .... you always have to disable email shield to work.

[DavidR]

This is a problem going for years , it never gets fixed .... you always have to disable email shield to work.

Well I have only been using Avast Free for 20 years and have never experienced this.

Mind you I only download emails from my ISP email server using SMTP, I have a google account and I don't pull those down, but view them in my browser.