Question Old iMac + Thunderbird -->! New iMac + Thunderbird.

[BarkingGhostar]

Background: Back in 2010 I bought my wife her first Apple iMac (27", 4K i7) computer. Because she had many email accounts on her own personal domain, I simply migrated her Mozilla Thunderbird client from a then Windows 7 computer to this new iMac. Everything worked and still works to this very day.

Current: In early 2016 I bought a B-stock iMac (27", 5K Retina, i5) computer and it never really got used. Then early this year I nuked and paved it and did an operating system fresh install via the Internet. I got all of her apps reinstalled manually, forgoing the Migration utility. But one app, Mozilla Thunderbord refused to work. I can get it installed, but not functioning. Innitally I simply did a manual client migration from the old iMac to the new one and existing email showed up in the client. But I could not get any email to download from the mail servers.

I then removed the Thunderbird app, did some manual cleanup to make sure no artifacts remained, and rebooted. I then installed the app anew and without trying to migrate the old Profile folder I went through the new client setup that Thunderbord has you do. Now, I used the information for an existing mailbox and kept getting the following error:

Could not connect to server pop.1and1.com; connection was refused.

OK, some other information: my original web hosting company was 1 and 1, but they recently got bought out by IONOS. I even tried to configure the existing account using the IONOS servers per their website information and still got the same error message. And during all of this troubleshooting I bought a Surface Pro 7 and in one move copied and pasted the Thunderbird folder from the old iMac to the SP7 and it worked perfectly, email is working like it should be.

So why can't I get this email client to work on the new iMac when I can do so on a new Windows box? Rhetorical question as no one has been able to successfully provide a working solution in the past five weeks. Not even the web hosting company can help.

BTW, I bought a seoncd SP7 this morning to setup for my wife and her Thunderbird email. This will effectively remove her from the Apple ecosystem with the exception of her iPhone, which she always buys the minimal offering.

 

[BarkingGhostar]

It is flipping amazing what happens when you sleep!

I got up just a few minutes ago wondering if IONOS actually requires IMAP for Thunderbird to work on a Mac. I literally Googled "thunderbird email only works on mac using imap server" and THIS link shows someone that had the exact same problem I have been going through and how it eventually got solved:

joy2meuKüsimuse esitaja
28.10.19 11:49
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Mac cleanup pro was causing it to set up a proxy server. Under System Preferences click Network - and then Advanced - and then proxies to see if one of them was checked. That is what I need to get it to stop doing - setting up the proxy was what was messing things up.

I founds a SOCKS proxy was checked and unchecked it. BAM! Fixed. joy2meu contacted Apple support which got solution promoted. Shockingly, this proxy wasn't checked on my 10 year old iMac. Other than M$ Office 2011 and Lightroom, the only other software I installed was Firefox, Thunderbird and Google Chrome.

What exactly setup this proxy is a mystery.

 

[BarkingGhostar]

Turned the new mac back on this morning, copied and pasted the contents of the Thunderbird folder on the old mac into the same folder on the new mac and launched the app. Without checking beforehand, the app launched but the original problem came back. I went looking in System Preferences/Advanced/Proxy and by golly the SOCKS proxy was checked again. I am not sure if this is something the macOs is doing on start/boot or if this is something that Thunderbird, or some other app is doing at system boot. I unchecked it and Thunderbird on the new mac is working perfectly.

 

[BarkingGhostar]

I gave up trying to find a solution beyond what was already being recommended to other mac users with the same exact problem. I installed Malwarebytes, ran it, found 22 items to quarantine, which I then removed (deleted). Re-ran again and found two more items, which I removed and on the third run ran clean. Uninstalled and checked for SOCKS and it wasn't enabled anymore.