The first thing you should do is check that there is enough free disk space on the disk where VPOP3 is installed. VPOP3 requires a certain amount of free space before it will allow new messages to be sent, so the disk might not be totally full, but VPOP3 will still report that there is insufficient disk space when you try to send a new message. This buffer zone is designed to help prevent the disk totally filling up, which can cause lots of bigger problems!

If there is plenty of free disk space on the disk where VPOP3 is installed and VPOP3 is still reporting an insufficient disk space error, then check that the error is being generated by VPOP3, and not by your ISP. VPOP3 will report errors that have been generated by your ISP and it's easy to assume the VPOP3 machine is at fault when it is not. As a general rule,

• If the error message appears in the VPOP3 status window, or in an email returned to the message sender, then the out of disk space error is being generated by your ISP and you will need to contact them. The exact error text that VPOP3 uses for reporting this error is 452 4.3.1 Insufficient Disk space to send mail. In essense, VPOP3 is saying that it tried to send the mail but the ISP was unable to accept it due to a lack of disk space.
• If the error appears as a popup window or in a progress window in your email client, then the error is being generated by VPOP3. If you are certain there is enough free disk space on the disk where VPOP3 is installed then you should check the disk space buffer zones and if that does not explain the problem, contact support@pscs.co.uk, with the details of the exact error message you receive, the amount of free disk space on the VPOP3 installation disk, the version of Windows, and the version of VPOP3.

You can turn off the disk space checks in VPOP3, but this is not recommended - if the disk fills up and disk space checking is turned off, you may lose messages and/or VPOP3 settings! To turn off the disk space checks in VPOP3:

Go to Settings → Misc Settings → Disk/Memory Checking and untick Enable disk space checking.

Go to the Utilities → Misc Settings page in the VPOP3 settings and untick 'Enable disk space checking'.

You will have to edit the registry manually as below:

• Close VPOP3
• Run Regedit, and find HKEY_LOCAL_MACHINE\SOFTWARE\PaulSmith\VPOP3\Secret
• Create or edit a DWORD value called CheckDiskSpace and set it to 0 (zero)
• Restart VPOP3

Go to Settings → Misc Settings → Disk/Memory Checking. There is a section called Disk Space Checking. This has the 4 different disk space checking settings, along with an explanation of what they mean.

Go to the Utilities → Misc Settings page in the VPOP3 settings. There is a section called Disk Space Checking. This has the 4 different disk space checking settings, along with an explanation of what they mean.

You will have to edit the registry manually as below:

• Close VPOP3
• Run RegEdit and find HKEY_LOCAL_MACHINE\Software\PaulSmith\VPOP3\Secret
• The SMTPDiskSpaceSpare setting is the number of MB (megabytes) which must be available on the disk before VPOP3 will accept any new SMTP messages
• The SMTPDiskSpaceSpare2 setting is the number of MB (megabytes) which must be available on the disk after a message has been received using SMTP, before VPOP3 will continue to process the message
• The POP3DiskSpaceSpare setting is the number of MB (megabytes) which must be available on the disk before VPOP3 will start a POP3 download session
• The POP3DiskSpaceSpare2 setting is the number of MB (megabytes) over the size of a particular message before VPOP3 will download that message using the POP3 protocol.