Things have moved on, and I have further information to report. No apologies for any duplicate information below - I thought it best to set the whole thing out carefully.
For at least a couple of months now, I have had a really strange problem. Most of the time, my email has worked properly, but occasionally it has played up at those times I can send emails, but not pick them up. I have spent time on the phone with my ISP, and they found nothing. To bypass Windows during the problem, I tried pinging the POP3 mail server from a command window no response. And at the same time I tried pinging the SMTP (outgoing mail) server all fine.
This problem has no other symptoms, and no other software seems to be affected.
I use a Belkin wireless modem / router, connected to the phone line (ADSL), and by Ethernet wire to my PC. For email I use Thunderbird. This setup has been the same for several years, except I got a new PC in autumn 2013, and there were no problems at that stage. The new PC uses Windows 7.
Sometimes re-starting Windows has fixed the problem for a while and sometimes it hasnt. Switching the PC right off and on again gets things working properly, until the next time.
In the course of trying to fix this, I found this page and it started me wondering about the MTU settings. Full disclosure I had never heard of MTU before.
In the PC, the MTU is set to 1500, as below. In the modem / router it is set to 1400; I dont know if having two different settings like that is a problem. And looking at the sevenforums page, I wonder if I should reduce the 1500 to 1472. I hesitate to do that because I do not appear to be suffering packet loss.
Microsoft Windows [Version 6.1.7601]
Copyright (c) 2009 Microsoft Corporation. All rights reserved.
C:\Users\Brian>netsh interface ipv4 show subinterfaces
MTU MediaSenseState Bytes In Bytes Out Interface
------ --------------- --------- --------- -------------
4294967295 1 0 343613 Loopback Pseudo-Interface 1
1500 1 28596266 2215303 Local Area Connection
1500 1 0 337019 Local Area Connection 2
1500 1 0 348593 VirtualBox Host-Only Network
A couple of weeks ago, I installed a VPN for the first time. I dont routinely have the VPN on, because its free so I have limited bandwidth. I have found that, when the problem occurs, all I have to do is switch on the VPN, and I can collect email. Is this a clue?
For at least a couple of months now, I have had a really strange problem. Most of the time, my email has worked properly, but occasionally it has played up at those times I can send emails, but not pick them up. I have spent time on the phone with my ISP, and they found nothing. To bypass Windows during the problem, I tried pinging the POP3 mail server from a command window no response. And at the same time I tried pinging the SMTP (outgoing mail) server all fine.
This problem has no other symptoms, and no other software seems to be affected.
I use a Belkin wireless modem / router, connected to the phone line (ADSL), and by Ethernet wire to my PC. For email I use Thunderbird. This setup has been the same for several years, except I got a new PC in autumn 2013, and there were no problems at that stage. The new PC uses Windows 7.
Sometimes re-starting Windows has fixed the problem for a while and sometimes it hasnt. Switching the PC right off and on again gets things working properly, until the next time.
In the course of trying to fix this, I found this page and it started me wondering about the MTU settings. Full disclosure I had never heard of MTU before.
In the PC, the MTU is set to 1500, as below. In the modem / router it is set to 1400; I dont know if having two different settings like that is a problem. And looking at the sevenforums page, I wonder if I should reduce the 1500 to 1472. I hesitate to do that because I do not appear to be suffering packet loss.
Microsoft Windows [Version 6.1.7601]
Copyright (c) 2009 Microsoft Corporation. All rights reserved.
C:\Users\Brian>netsh interface ipv4 show subinterfaces
MTU MediaSenseState Bytes In Bytes Out Interface
------ --------------- --------- --------- -------------
4294967295 1 0 343613 Loopback Pseudo-Interface 1
1500 1 28596266 2215303 Local Area Connection
1500 1 0 337019 Local Area Connection 2
1500 1 0 348593 VirtualBox Host-Only Network
A couple of weeks ago, I installed a VPN for the first time. I dont routinely have the VPN on, because its free so I have limited bandwidth. I have found that, when the problem occurs, all I have to do is switch on the VPN, and I can collect email. Is this a clue?