IMAP traffic being blocked — with or without rule

[kalanga]

Lulu is blocking some incoming IMAP traffic. Version 2.0.0 on Big Sur. Start of this issue coincides with the installation of Big Sur (roughly).

Symptoms:

• Airmail and Apple mail can send IMAP mail but cannot receive mail when Lulu is turned on (and function perfectly when Lulu is turned off) even though these apps are allowed all network access

Attempted fixes:

• Creating rules to allow any processes to connect any address on ports 993, 995, 465, 587
• Uninstalling and reinstalling Lulu with new rules
• Passive mode

[objective-see]

Thanks for the bug report!

After some digging, this appears to be an issue affecting any client (firewall, etc) that leverages Apple Network Extension framework

For example:

• IMAP timing out in Apple Mail in Big Sur
• MACOS BIG SUR ISSUE: Mail stops working if another app using Net

"It seems any app that uses System Extension which filters network connections. We have reproduced it with: Cisco AnyConnect Little Snitch firewall Microsoft Defender"

As this is likely an Apple bug (or at least not specifically a LuLu bug) I've submitted a bug report to Apple (FB8909991).

Apple recommended that others experiencing this issue should also submit a report (which you can do via macOS Feedback Assistance.app).

[siddiqq]

Thanks for the bug report!

After some digging, this appears to be an issue affecting any client (firewall, etc) that leverages Apple Network Extension framework

For example:

• IMAP timing out in Apple Mail in Big Sur
• MACOS BIG SUR ISSUE: Mail stops working if another app using Net

"It seems any app that uses System Extension which filters network connections. We have reproduced it with: Cisco AnyConnect Little Snitch firewall Microsoft Defender"

As this is likely an Apple bug (or at least not specifically a LuLu bug) I've submitted a bug report to Apple (FB8909991).

Apple recommended that others experiencing this issue should also submit a report (which you can do via macOS Feedback Assistance.app).

Could this be related to why Apple Music is having problems updating the library with Lulu?

[Enterprise-D]

This issue seems to be persistent through at least MacOS 14.1.1