Comodo Firewall and Outlook express

Installed Comodo about 4 weeks ago. Working fine. All of the sudden I stated having trouble acceessing my e-mail through Outlook Express (no previous problems before).

Turned off Firewall and OE worked. Back on same problem. Oddly, I haven’t changed a thing with Firewall or OE. What did I do wrong. Advice?


I had a similar problem after some windows updates (including installing IE 7). What worked for me was deleting the CPF application rules for OE and then rebooting. The next time I used outlook CPF asked me whether I wanted to allow OE and it has worked fine ever since.


As anderow touches on - Windows updates can have an adverse effect. As OE is part of Windows it is therefore subject to updates from MS. One thing is for sure though - if you use another 3rd party email client (eg Pegasus) you’d probably have less problems. Bear in mind that OE uses the IE rendering engine and exploits from IE are easily carried over to OE because of this. And as such updates to the IE engine will also affect OE. So your culprit could be Windows Updates have changed something, if you say you did not alter either CPF or OE.

Of course, you could just do what anderow did, and delete the app rules for OE and start again. But i would suggest you find out from one of the mods in these forums exactly what can cause this, and why it happened in your case. At least that way you can learn some more about this great firewall.


If indeed your problem is related to an update (which is a common situation), here’s what happens:

CPF monitors applications on your computer that are allowed to communicate to the internet. If the cryptographic signature of the application changes (such as through an update to the application), in CPF’s eyes it is no longer the same application. In this type of situation, you should get a popup from CPF to alert you to this (it will say the signature has changed, etc).

If your Alert Frequency settings are turned off, or low (Security/Advanced/Miscellaneous - top two checkboxes, slider in the middle), you may not see a popup. OE is a known “safe” application, thus if you have the box checked for “Do not show alerts for applications certified by Comodo” you wouldn’t get a popup; if the signature didn’t fit, CPF would just block it (you can check Activity/Logs to find the blocking reference).

As anderow pointed out, if you remove the OE rules from the Application Monitor and reboot, you should get alerts for it.

Hope that helps,


I eliminated the rules for OE and incresed alert frquency - no help

Just to make sure… did you reboot your computer after removing the rules and changing alert frequency?

In Security/Advanced/Miscellaneous, make sure you uncheck the box “Do not show alerts for applications certified by Comodo” (this is the 2nd box from the top). Click OK. Reboot.

If after these two things you still have no joy, check the logs - Activity/Logs. You’re looking for firstly for warnings from the Application Monitor about OE, secondly for warnings from the Network Monitor at the time you tried OE. You can export the logs as an HTML file (where you can edit out your IP address and any personal information) and copy/paste here as text.


PS: At this point, after making any changes to rules or configuration of CPF, please reboot; this will make sure that the memory is cleared out and the changes accepted by CPF.