I contacted EM Client support and they clearly stated that the have had several call on this exact issue and asked the customer to contact BT support and apparently BT fixed the issue for some and dismissed others with the old get out !!!, nothing to do with us. Must admit though EM Client support have gone very quiet indeed since I emailed them the piffle that BT provided, lets see what happens.
LOL we are talking about BT they don’t know what they are doing !!!
I won’t comment on my experiences with BT “Support” 
Those of you who say accessing the Yahoo mail servers directly doesn’t work for them - do you mean it doesn’t work at all ? Or it does work but with the same underlying issues as before ??
I have just sent a test message from my hotmail account to my BT one
The message stuck coming in and I had the three dots
I ran repair on the inbox and it apeared
Thanks for pointing out the repair option - I didn’t know that tab was there !
Pete. I just get a red triangle when I change it to Yahoo mail server.
Have you run diagnostics on the account?
This is what I got at first - until I changed the login name in the Authentication tab to the full email address rather than the login name - i.e. changed “fred.blogs” to “[email protected]”. I use the identity credentials in the IMAP and SMTP settings so you only have to change them in the General Authentication settings.
May also be worth doing the repair Steve did which clears the cache ?
I have just sent another test message from my hotmail account to my BT one
The message stuck coming in and I had the three dots
I ran repair on the inboxagain and it apeared
I did a second test in case it was a fluke the first time
Perhaps one of all those contributing could try the same please?
Is it emclient sticking on receiving from BT
Had a bit of relief for an hour now its gone again saying I am not connected to the server and I could’n restart EM Client without rebooting, they were supposed to phone me today between 10-12 got a message left at 12:30 saying they will call between 5-7pm tomorrow, look forward to it, NOT !
Hello all,
Thank you for reporting the problems with BT mail servers and we’re sorry to hear about it.
Our developers examined the logs of these errors and came to the conclusion that it’s a server issue which can’t be fixed on our side. It seems that the BT updated the feature on their back-end servers but didn’t adapt the proxy servers which report the errors. It seems that BT is continuously changing the settings and that’s why sometimes the account reset helps but later on the issue reappears.
Here I’m re-posting an UNTESTED fix which from one of our customers:
"A bit of research reveals that BT use two versions of mail - BT email and BT Yahoo email.See here
http://bt.custhelp.com/app/answers/detail/a_id/57483/~/im-not-sure-if-ive-got-bt-mail-or-bt-yahoo!-mail
By logging into the desktop version of BT email you can see which version you have got. It transpires I have BT Yahoo mail. I have set the email up using BT Yahoo settings and it is now working again.Something must have changed on BT’s side. So if you get this query again this should be the solution."
Russel
Tried this, I am on BT Yahoo mail, but get a authentificationfailed error returned on IMAP once I have changed the server to imap.mail.yahoo.com which I find bizarre. Are we also saying that BT will continue their behavior going forward. Doesn’t work for me.
Can someone who has a PRO Licence for eMClient not get eMClient to sort this out with BT? I only have the free one
I tend to get greatly concerned that BT’s infrastructure is in such an unmanageable state that improvements may not be forthcoming any time soon, it amazes me that BT who supposed to know what they are doing have complete disregard for their customers, find it all rather sad.
I would like to report that my link to BT is now working
I have sent a test message and it arrives within seconds
my connection is intermittent sometimes I get an hour or so where I can use EM Client without any issues and other times it’s damned impossible to get it working, not happy !
Incredibly confusing situation it seems! Have been getting the same error messages when trying to download for the last few days. I.e:
“…cannot open folder…@btinternet.com/Inbox [Clientbug] Select additional arguments found after last expected argument)”
…same repeat message for
…/Trash
…/Drafts
…/Junk email
…/Archive
Have for some time had mail.btinternet.com server references for an IMAP account and only just in the last few days the reams of these error messages, before that just intermittent small glitches!!
My usual approach - wait a few hours and the problem goes away without me doing anything!
But good news (?) despite all the error messsages I am still receiving BT emails in the emC application. Just is taking longer to report all this extra rubbish!
No errors reported on a mobile device with a copied pop3 set up for the same BT email account with the default email programme on a Samsung galaxy android phone.
So from my non-technical perspective anyone’s guess what the underlying issue is!!!
What is BT, please?
British Telecom one of the largest broadband suppliers in the United Kingdom and one of the worst.
Have a look at Russels post, seems to be spot on to me.