Whacky email problem sending to btinternet.com

[#1]

My mum runs an Apple Mac OS 10.6 and uses the Apple email client.  Her ISP is BT and she uses BT Yahoo mail as her mail server.
She has a whacky problem in that when I send her an email (from Plusnet), her mail client downloads the email then locks up.  It will not download any more email from BT Yahoo, nor allow her to delete emails. Other emails are still arriving in her BT Yahoo mailbox and she can see them via her webmail, but the Apple mail client won't download them.
The email I send is plain text so nothing strange.  It is only email from me that causes the problem with my mum's mail client.
She can receive mail from others no problem, and I can send email to others no problem.
BT and Apple 'say' it is a problem with my ISP but I am not convinced.
Has anyone any ideas what the problem could be?
Also, mum is not technically minded and lives a long way away so it is not easy to diagnose the problem over the phone (and I can't email).

[#2]

Quote from: cjags

The email I send is plain text so nothing strange.  It is only email from me that causes the problem with my mum's mail client. She can receive mail from others no problem, and I can send email to others no problem.

It that literally "you", ie does "others" include emails from other Plusnet customers?
How do you create the message? Does the same happen if you use webmail (for example both Roundcube and SquirrelMail)

[#3]

Quote from: spraxyt

It that literally "you", ie does "others" include emails from other Plusnet customers?

I don't know if others includes Plusnet customers. I don't have visibility of mum's mail client.

Quote

How do you create the message?

Plain text message in Thunderdird.

Quote

Does the same happen if you use webmail (for example both Roundcube and SquirrelMail)

I don't know. Mum is not keen on me sending test emails to see what happens because it takes her a long time on the phone to BT to get it sorted.

[#4]

Hi cjags,

Quote

Mum is not keen on me sending test emails to see what happens because it takes her a long time on the phone to BT to get it sorted.

I'm a bit confused, Why should she need to get on the phone to BT each time?
Just login to squirrel mail, send a message subject "Sent from Squirrel Mail" with a line of text saying This is a test message from cjags.
Do the same with Roundcube, subject "Sent from Roundcube".
Ring your Mum up sometime after and just ask her if she got either of them and post back the answers here. Leave BT out of it for the moment.
Now as an aside for the moment, BT use Yahoo to provide mail services for many of their customers. I've read another post where mail to a Yahoo recipient is bouncing - I'm off to do some test mails. I'm wondering if the Trend Blacklist problem may be affecting Yahoo now.
Edit: sorry, I forgot to ask "Doesn't a machine reboot resolve the lock-up issue?" Whatever advice/solution BT gave the last time can't she just do it again - or was it a case of them logging in via remote assistance?

[#5]

I've sent some test emails to yahoo addresses with no problem, so unlikely to be related to server blacklisting.

[#6]

Quote from: Anotherone

I'm a bit confused, Why should she need to get on the phone to BT each time?

Because they can get her email client talking to BT Yahoo again.
I expect the Apple helpline could too but she has to pay extra for them.

Quote

Just login to squirrel mail, send a message subject "Sent from Squirrel Mail" with a line of text saying This is a test message from cjags. Do the same with Roundcube, subject "Sent from Roundcube". Ring your Mum up sometime after and just ask her if she got either of them and post back the answers here. Leave BT out of it for the moment.

That isn't going to work.  I would have to send one email only.  Find out if that caused a lock up.  If it did, I will have to wait until she has unjammed the mail client and then send the second mail.  Unfortunately, she doesn't have the time or patience to get to the bottom of this and is convinced it is my fault so I should be able to fix it just like that.
I can get another Plusnet user to send her an email to see if that jams up the apple mail client.  If it does, it will be their fault not mine

Quote

"Doesn't a machine reboot resolve the lock-up issue?" Whatever advice/solution BT gave the last time can't she just do it again - or was it a case of them logging in via remote assistance?

A restart doesn't work and she doesn't know how to repeat the advice BT gave her.  It could be that they did remote connect to sort the problem.  I have no idea and neither does my mum.  The only information I can get from mum is that after the apple mail client has downloaded my email (from BT Yahoo) it will not get any more emails or allow her to delete any emails.  The only way she has of fixing the problem is to phone BT and get them to fix it (somehow) which takes about an hour.
It is unlikely to be server blacklisting because she gets my email, it's just that she doesn't get anymore afterwards.
All I can think of is there is something strange in the message headers OR a whacky attachment has been added, but trying to get mum to email the message headers back to me is not easy.
Also, I don't have access to an Apple mac to set up a test system.

[#7]

Quote

Unfortunately, she doesn't have the time or patience to get to the bottom of this and is convinced it is my fault so I should be able to fix it just like that

Typical mothers

Quote

The only way she has of fixing the problem is to phone BT and get them to fix it (somehow) which takes about an hour.

Oh, ouch, I hope the call isn't costing her!
Try posting a short post on the Mac/Linux board outlining the problem and giving a link to this thread in the hope someone knowledgeable there can come here and take a look.

[#8]

I'm not sure what system BT Yahoo are using for their pop3 access but in the past I've used MacFreePops to download emails from a standard yahoo mail account. With that system I always had problems with it stopping and refusing to download all messages in one go.
Do you know if your mum had to install software on to the mac for mail access? Or is the access IMAP based? I certainly don't think it is Apple Mail that is locking up, more likely a system elsewhere is choking up and stopping access.
Maybe your mum could try using Thunderbird, see if it happens the same there. If there's some online help about setting up BT Yahoo mail, please point me to it.

[#9]

It's pretty basic - http://bt.custhelp.com/app/answers/detail/a_id/6876/~/what-are-the-bt-yahoo!-mail-settings-for-outgo...

[#10]

Thanks Jaggies, definitely explains what connection they're using.
I'm not entirely sure what's going on at the end user. I'd like to know if the Mail app is "beach balling" or is totally unresponsive to all user interaction in some way.
I certainly can't think of anything inside an plain email that could cause the simptoms you've mentioned. First things I would try in that situation would be to open Disk Utility and run a check on the HD & repair disk permissions.

[#11]

Quote from: RPMozley

Do you know if your mum had to install software on to the mac for mail access? Or is the access IMAP based?

I did ask and all she could tell me is that it is Apple Mac Email. So I am guessing it is an email client that comes as standard on a Mac.
No idea if POP or IMAP.
I will be seeing her next month so might be able to find out a bit more when I am there.

[#12]

Quote from: cjags

I did ask and all she could tell me is that it is Apple Mac Email. So I am guessing it is an email client that comes as standard on a Mac. No idea if POP or IMAP. I will be seeing her next month so might be able to find out a bit more when I am there.

Apple's Mail application comes with Mac OS X, so yes it is standard.
Don't worry about POP or IMAP, as shown in the link Jaggies shared it states that it is using POP3 access. So in my mind that isn't the source of the problem.
The things to check are:
1) See the exact problem firsthand and note down what happens, things like the Mail application either showing a spinning beach-ball when moving the mouse over the window, just not able to do certain things within the program or can't do anything including quitting the application.
2) Use Disk Utility application to check the disk and "Repare Disk Permissions".
3) One possible long shot, see if you can open the address book in Mac Mail.
Anyway, good luck next month. Hope you can find out what the problem is and solve it.