Windows Live Mail error 0x8007007A in Windows 10 when sending to SMTP

My father's Windows 7 PC was upgraded to Windows 10. He uses Windows Live
Mail - not sure which version but it's either V2011 or V2012 with the ribbon
interface.

Since the upgrade to Win 10, he has started occasionally getting error
0x8007007A ("an unknown error has occurred", according to the dialog box)
when sending email: the error message refers to protocol SMTP, port 25 and
his ISP's SMTP server address, so it's definitely an SMTP rather than POP
problem. It seems to be more common if he sends an email with more that one
attachment - I'm not sure what size of attachments he's sending.

His ISP is Plusnet and the port, server and SSL/no SSL settings are correct
for Plusnet's POP and SMTP servers. He's not using a Microsoft-owned mail
account such as Outlook.com, Hotmail etc.

I know that there are a few problems with WLM on Windows 10 which are partly
fixed by a KB update, but as far as I can tell, this only affects problems
with Outlook.com.

The error code 0x8007007A is listed on Microsoft's support site but only in
the context of Windows Update problems, not Windows Live Mail.

He is used to using WLM and would really prefer NOT to have to change to a
different mail client such as Thunderbird or, even worse, a Metro-UI app
such as Windows Mail.

Any suggestions?

Why is it that Microsoft cannot achieve the simple task of all versions of
its mail clients and browsers working on all versions of Windows? Do any
other software companies have such a reputation for forcing people to update
their applications every time they upgrade Windows? Whatever happened to
backward compatibility?

On 10/07/2016 22:32, NY wrote:


Any suggestions?



Have you tried creating a new windows profile (this is same as creating
a new user account) and then try from that new account? I suspect it is
something to do with permissions issues and or SMTP settings but before
doing anything, you need to try creating a new account and then try again.

I believe you said this:

He is used to using WLM and would really prefer NOT to have to change
to a
different mail client such as Thunderbird or, even worse, a Metro-UI app
such as Windows Mail.

Unfortunately, WLM is a very old program and Windows 10 is pretty new
Operating system. Old codes in WLM may not necessarily work in Windows
10 but some people are quite happy using it in Win 10.


--
With over 350 million devices now running Windows 10, customer
satisfaction is higher than any previous version of windows.

NY wrote:
My father's Windows 7 PC was upgraded to Windows 10. He uses Windows Live
Mail - not sure which version but it's either V2011 or V2012 with the
ribbon
interface.

Since the upgrade to Win 10, he has started occasionally getting error
0x8007007A ("an unknown error has occurred", according to the dialog
box) when sending email: the error message refers to protocol SMTP, port
25 and his ISP's SMTP server address, so it's definitely an SMTP rather
than POP problem. It seems to be more common if he sends an email with
more that one attachment - I'm not sure what size of attachments he's
sending.

His ISP is Plusnet and the port, server and SSL/no SSL settings are correct
for Plusnet's POP and SMTP servers. He's not using a Microsoft-owned mail
account such as Outlook.com, Hotmail etc.

I know that there are a few problems with WLM on Windows 10 which are
partly
fixed by a KB update, but as far as I can tell, this only affects problems
with Outlook.com.

The error code 0x8007007A is listed on Microsoft's support site but only in
the context of Windows Update problems, not Windows Live Mail.

He is used to using WLM and would really prefer NOT to have to change to a
different mail client such as Thunderbird or, even worse, a Metro-UI app
such as Windows Mail.

Any suggestions?

Why is it that Microsoft cannot achieve the simple task of all versions of
its mail clients and browsers working on all versions of Windows? Do any
other software companies have such a reputation for forcing people to
update
their applications every time they upgrade Windows? Whatever happened to
backward compatibility?

Have a look at this article.

"Troubleshooting PMTU Black Hole Routers"
https://technet.microsoft.com/en-us/.../cc958871.aspx

The problem arises on mail servers, when the ISP decided
to disable ICMP protocol (which stops you from being
able to "ping" their server, but also prevents proper
handling of the "Do not fragment" protocol).

There could be some difference in how the
two OSes handle this corner case in their protocol
stacks. Notice in the article, that the registry key
in question, isn't even in the registry, and must
be added by the user.

You can debug this with Wireshark, see a single 1500 byte
packet with the message body in it, leave your end. And
after that, there is no response at all from the server.
That's a hint.

Just a wild wild guess,
Paul

NY wrote:

My father's Windows 7 PC was upgraded to Windows 10. He uses Windows
Live Mail - not sure which version but it's either V2011 or V2012
with the ribbon interface.

Since the upgrade to Win 10, he has started occasionally getting error
0x8007007A ("an unknown error has occurred", according to the dialog
box) when sending email: the error message refers to protocol SMTP,
port 25 and his ISP's SMTP server address, so it's definitely an SMTP
rather than POP problem. It seems to be more common if he sends an
email with more that one attachment - I'm not sure what size of
attachments he's sending.

His ISP is Plusnet and the port, server and SSL/no SSL settings are
correct for Plusnet's POP and SMTP servers. He's not using a
Microsoft-owned mail account such as Outlook.com, Hotmail etc.

I know that there are a few problems with WLM on Windows 10 which are
partly fixed by a KB update, but as far as I can tell, this only
affects problems with Outlook.com.

The error code 0x8007007A is listed on Microsoft's support site but
only in the context of Windows Update problems, not Windows Live Mail.

He is used to using WLM and would really prefer NOT to have to change
to a different mail client such as Thunderbird or, even worse, a
Metro-UI app such as Windows Mail.

Any suggestions?

Why is it that Microsoft cannot achieve the simple task of all
versions of its mail clients and browsers working on all versions of
Windows? Do any other software companies have such a reputation for
forcing people to update their applications every time they upgrade
Windows? Whatever happened to backward compatibility?

Have you tried port 587 istead of 25?




--

The KB that you mentioned 'fixing' WLM never had applicability to Win10. In
fact, that KB was deprecated and no longer available and only applied to
WLM12(not 11) on pre-Win10 o/s. The KB was an attempt to update
under-the-hood' code replacing DeltaSync with EAS - didn't work, caused
other crash and corruption problems with WLM's functionality - Send, Receive
and Indexing.


Plusnet settings
https://www.plus.net/help/email-guid...plusnet-email/
Expand and read the section titled - 'What other settings do I need'
For SMTP - use 587 instead of 25.

Verify, for validation purposes, the correct settings are in use for POP3,
Authentication, Incoming Port, etc.

Optionally, if you can setup the same account in WLM using IMAP **and** it
functions properly then your issue could be one of two primary causes.
1. PLusNet Mail servers (Check Plusnet site's Server Status)
http://www.plus.net/supportpages.html?a=2

2. Corruption in the email account in WLM

If the latter, access the account's properties(Server tab) in WLM and remove
the password, click apply, close the Properties dialog box and perform a
send and receive, when prompted enter the correct password, and choose
'Remember Password'.


--
....winston
msft mvp windows experience

"NY" wrote in message
o.uk...

My father's Windows 7 PC was upgraded to Windows 10. He uses Windows Live
Mail - not sure which version but it's either V2011 or V2012 with the ribbon
interface.

Since the upgrade to Win 10, he has started occasionally getting error
0x8007007A ("an unknown error has occurred", according to the dialog box)
when sending email: the error message refers to protocol SMTP, port 25 and
his ISP's SMTP server address, so it's definitely an SMTP rather than POP
problem. It seems to be more common if he sends an email with more that one
attachment - I'm not sure what size of attachments he's sending.

His ISP is Plusnet and the port, server and SSL/no SSL settings are correct
for Plusnet's POP and SMTP servers. He's not using a Microsoft-owned mail
account such as Outlook.com, Hotmail etc.

I know that there are a few problems with WLM on Windows 10 which are partly
fixed by a KB update, but as far as I can tell, this only affects problems
with Outlook.com.

The error code 0x8007007A is listed on Microsoft's support site but only in
the context of Windows Update problems, not Windows Live Mail.

He is used to using WLM and would really prefer NOT to have to change to a
different mail client such as Thunderbird or, even worse, a Metro-UI app
such as Windows Mail.

Any suggestions?

Why is it that Microsoft cannot achieve the simple task of all versions of
its mail clients and browsers working on all versions of Windows? Do any
other software companies have such a reputation for forcing people to update
their applications every time they upgrade Windows? Whatever happened to
backward compatibility?

NY wrote:

My father's Windows 7 PC was upgraded to Windows 10. He uses Windows Live
Mail - not sure which version but it's either V2011 or V2012 with the ribbon
interface.

Since the upgrade to Win 10, he has started occasionally getting error
0x8007007A ("an unknown error has occurred", according to the dialog box)
when sending email: the error message refers to protocol SMTP, port 25 and
his ISP's SMTP server address, so it's definitely an SMTP rather than POP
problem. It seems to be more common if he sends an email with more that one
attachment - I'm not sure what size of attachments he's sending.

His ISP is Plusnet and the port, server and SSL/no SSL settings are correct
for Plusnet's POP and SMTP servers. He's not using a Microsoft-owned mail
account such as Outlook.com, Hotmail etc.

I know that there are a few problems with WLM on Windows 10 which are partly
fixed by a KB update, but as far as I can tell, this only affects problems
with Outlook.com.

The error code 0x8007007A is listed on Microsoft's support site but only in
the context of Windows Update problems, not Windows Live Mail.

He is used to using WLM and would really prefer NOT to have to change to a
different mail client such as Thunderbird or, even worse, a Metro-UI app
such as Windows Mail.

Any suggestions?

Why is it that Microsoft cannot achieve the simple task of all versions of
its mail clients and browsers working on all versions of Windows? Do any
other software companies have such a reputation for forcing people to update
their applications every time they upgrade Windows? Whatever happened to
backward compatibility?

Disable e-mail scanning in your anti-virus software. It is superfluous
(adds no extra protection over the on-access/real-time scanner);
however, it will incur delays in delivery of e-mail traffic from server
to client and from client to server. The latter seems to be typically
the most sensitive to timeout errors with the addition of delays caused
by an intervening transparent proxy doing the e-mail traffic
interrogation.

"the error message refers to protocol SMTP, port 25". Although port 25
got used for a long time for clients (MUAs = Mail User Agents) to
connect to the servers (MTAs = Mail Transfer Agents), it was originally
intended only for connections between MTAs. After around 15 years, ISPs
and e-mail providers caught on that MUAs were supposed to use port 587
to connect to MTAs. As a consequence, a lot of ISPs block port 25
traffic over their network that did not originate or target their own
SMTP server; that is, port 25 traffic to and from their SMTP server was
okay (but some changed that, too) but not if an MUA attempted to connect
to an MTA that was off their network (aka off-domain) from the ISP for
that MUA.

Sounds more complicated than it is. Used to be port 25 was used for
clients to connect to SMTP servers, and that's how many e-mail clients
are configured in their helpful auto-config database. Eventually
clients were supposed to use 587 (although port 25 may still be
supported). With the switch to port 587, many ISPs eventually block
port 25 traffic across their network. So users had to reconfigure their
e-mail clients to use port 587 when connecting to an SMTP server.

Another cause for connection troubles is some e-mail providers switching
from SSL connects to TLS connects to theri SMTP server. SSL is
considered insecure (e.g., Heartbleed vulnerability). So many e-mail
providers mandated use of TLS to connect to their SMTP server. If your
e-mail client does not support TLS then you cannot use it to connect to
their SMTP server. I ran into this with Outlook 2003 which did not have
TLS support. When Microsoft mandated a change to using TLS to connect
to their SMTP server, Outlook 2003 became unusable to me for sending
e-mails via SMTP through Microsoft (Hotmail). I had to move up to a
newer e-mail client that had TLS support.

So check if port 587 is specified for the SMTP server connection. Also
check that either TLS or Auto (tries TLS first, then falls back to SSL)
is selected for the connection protocol. Just because you changed
nothing on your end does not mean the e-mail provider didn't change
their setup or that your ISP started blocking off-domain port 25
traffic. Things change but the settings in your client are static.

"NY" wrote in message
o.uk...

My father's Windows 7 PC was upgraded to Windows 10. He uses Windows Live
Mail - not sure which version but it's either V2011 or V2012 with the ribbon
interface.

Since the upgrade to Win 10, he has started occasionally getting error
0x8007007A ("an unknown error has occurred", according to the dialog box)
when sending email: the error message refers to protocol SMTP, port 25 and
his ISP's SMTP server address, so it's definitely an SMTP rather than POP
problem. It seems to be more common if he sends an email with more that one
attachment - I'm not sure what size of attachments he's sending.

His ISP is Plusnet and the port, server and SSL/no SSL settings are correct
for Plusnet's POP and SMTP servers. He's not using a Microsoft-owned mail
account such as Outlook.com, Hotmail etc.

I know that there are a few problems with WLM on Windows 10 which are partly
fixed by a KB update, but as far as I can tell, this only affects problems
with Outlook.com.

The error code 0x8007007A is listed on Microsoft's support site but only in
the context of Windows Update problems, not Windows Live Mail.

He is used to using WLM and would really prefer NOT to have to change to a
different mail client such as Thunderbird or, even worse, a Metro-UI app
such as Windows Mail.

Any suggestions?

Why is it that Microsoft cannot achieve the simple task of all versions of
its mail clients and browsers working on all versions of Windows? Do any
other software companies have such a reputation for forcing people to update
their applications every time they upgrade Windows? Whatever happened to
backward compatibility?
++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++

Go to "control panel"
open "Programs and features"
Click on "Windows essentials"
Click on the "repair all Windows Essentials programs"

Perhaps it will help.