Gmail unaccessible with Evolution / Thunderbird etc

Dear all,
Has anything major changed in order to access gmail with a 3rd party client?

It is now impossible for me to access it with either Evolution, Thunderbird and even Android clients like K9 and Aquamail.

However, access with a web browser works.

In my google account settings 2FA and usage of the phone to sign in are switched off, but none of the above works.

Evolution and Thunderbird try to connect forever.



Since you mention that the behavior is seen in other clients the cause seems to be somewhere in the connection between the parties.

Some practical info to add to your post and some tips on how to request support:

However since the behavior is also seen on Android (I presume you use them form the same network?) this leads me to conclude the issue you are experiencing is not caused by specific software on your devices and this forum would be the wrong place to request support for your issue.

For reference I use Evolution & Android have 2 gmail accounts and do not experience the issues you describe.

You must use oauth2 as authentication method. Select it in Thunderbird’s account settings.

Make sure you have “Allow insecure applications” turned on in Google settings.

Anything Google has not made is counted as insecure to Google, so this setting needs to be turned on.
And it has a habit of turning itself off from time to time.


Thanks to everyone.

Hanzel’s post made think about a possible systemic cause. Thus, I started to experiment with the Firewall settings of my router which can be set to Low, Medium and High.

It was on high and thus blocking connection. Once set to low or off, it would allow connections.

Interestingly, the router is a Vodafone station and runs linux. However, there are no settings to allow easy pass through on either application or port specific basis.

I would prefer to have the firewall on high, but I guess there is no other option at the moment.

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You should contact your ISP if you got the modem from them to replace it with one who does have settings like that.
Another way might be using an UPnP client to punch a hole you need if your modem reacts to UPnP.

If all fails just disable the firewall on the modem completely and use the firewall of your Linux :wink:

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What’s the connection between a firewall and Thunderbird?

Did you try oauth2?

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Your ISP/ might block access to external sites for a variety of reasons. The traffic you generate is a flag in a filter that is targeted to block on the ISP box:

  • Malicious activity (this could be the previous user of the IP your traffic originates from of you share your connection with something/one malicious)
  • Protocols that are valid but are know to be misused/exploited/generate to much effort for the ISP (older or legacy/expensive traffic)
  • Your ISP blocks services that they sell/provide themselves, I doubt this but it can happen.
  • The ’ high’ filter is suboptimal. :crazy_face:


1 Check that the connection is made in a ‘modern way’ eg do not use imap or pop3

2 Contact your ISP (or your ISP user community) explain your issue and ask for a solution.

Some incoherent thoughts:

The high setting might as well be a deny all when something as basic as a secure connection to a worldwide serviceprovider does not function(this does depend on where one lives tho). I am hesitant to give advice on how one should configure ones network since there are different solutions out there and there is no info on the type/provider/country of the connection. As a rule of thumb, most if not all ISP boxes block everything from outside going in and provide NAT & UPnP out of the box (in my part of the world). For more complex protocols (using gmail should not fall into that category) a UPnP solution could be configured.

I am intrigued what high should accomplish on the device since the only option a service provider should provide to keep you safe is the blocking of external traffic and accept internal traffic.
So what are the medium low and none options for?

The high/medium/low/none setting, to me, seems useless and provides a false sens of ‘am I safe’, eg how can one be ’ medium secure’, a internet connection is not a hamburger, but I digress, please forgive me, it is a excellent query on the support page of the service provider, my guess is it is next to the page that gives the advice to not open links you do not trust.

What would be the “modern” protocol alternative to imap for gmail? I am unaware of it.

In addition to imap, the firewall on high also blocks whatsapp voice calls. Messaging instead is fine.

I saw something similar happening at friends place, where setting the router firewall on “high” even blocks connection to streaming services like Netflix etc.

There must be a way to log-in the router and have a more granular control. However, I doubt ISP tech support would tell me how.

Are you in a repressive country? Then maybe not even a VPN would work.

If it’s only the router settings, disable the firewall (it’s stupid anyway as you see).