The External Mail -> Connection Settings page tells VPOP3 how to connect to the Internet (or remote network). VPOP3 supports two methods, which actually cover the vast majority of possible connection methods. The simplest way is via a LAN connection, but you can also use a Dial-up Connection. These two connection methods cover all standard connection methods from analogue modem, through ISDN, xDSL, to leased lines and other dedicated connections.
You can define up to 10 connection methods (except in the VPOP3 Home User licence where only 1 connection method is allowed)
Read
about the relationship between Connections,
In Mail and Out
Mail.

To add/remove Connection methods, use the External Mail -> Connection Selection page.
Each Connection method has a name. This name will be used if VPOP3 reports any errors when using the configuration, but it does not have any real significance - so it is impossible to set the 'Connection Name' to an incorrect value. To make it easier to keep track of which configuration is which, it is best to use a meaningful name, such as the ISP name.
You should first of all choose either a LAN connection (in which case many of the other fields are disabled) or a Dial-up connection. As a rule of thumb, use Dial-up connection if you connect to the Internet using the Windows Dial-up networking facilities, otherwise use LAN connection.
If you choose to use a dial-up connection method in VPOP3, you need to enter information in the following fields:
Dial-up Connection This will contain a list of all the Dial-up connections which are defined on your computer. Choose the one you wish to use for this Connection method.
User Name. This is the user name you use for connecting using the dial-up connection you have chosen.
Password. This is the password you use for connecting using the dial-up connection you have chosen.
Retries This defines the number of times you want VPOP3 to try and establish a dial-up connection.
Interval This lets you specify the time in minutes before VPOP3 will retry a connection. This is useful if VPOP3 will be sharing a modem with some other software (e.g. a fax server).
Timeout This is the number of minutes that VPOP3 will wait before cancelling a dial-up connection which isn't connecting properly. (Note, this does not allow VPOP3 to drop an idle RAS connection once it has been established properly. To do that, you will need to use the Socket Timeout entries on the Network Tweaks Page).
Use Multilink dial-up If VPOP3 is running on Windows NT, 2000, XP or 2003 then Windows is capable of linking two dial-up connections together to make a faster connection. Turning on the Use Multilink RAS option will enable that facility. (Note that this will probably be charged as two telephone calls by your telephone provider, so may be more expensive than a single call, especially if minimum call charges apply)
The Dial-up Connections which can also be used if established list contains a list of all the Dial-up connections which are configured on your computer. You should select any entries on this list which relate to alternate connection methods to your ISP. If VPOP3 is going to use this Connection method, and one of the selected dial-up connections is already active, then VPOP3 will use the active dial-up connection instead of trying to establish a new connection. You should ideally only specify those dial-up connections which link to the same ISP, NOT to other ISPs (create other Connection methods to connect to other ISPs).
VPOP3 has a feature where it can sense a dial-up session being set up by some other software or manually, and use it if possible for collecting and sending mail. This feature is called ‘AutoConnect’
AutoConnect is enabled if you check the Auto Connect when computer connected to valid dial-up connection box. When it is enabled VPOP3 will periodically check the connections selected in the list of Dial-up Connections which can also be used if established (see above) to see if they are active. If so, then VPOP3 will connect to the appropriate mail servers automatically.
There are two further settings for AutoConnect:
Only AutoConnect once per dial-up session. This means that VPOP3 will only connect to the Mail Server once, when it first senses that a dial-up session has been established. It will then not connect again, until the dial-up session has been dropped and re-established.
AutoConnect Period. This specifies the number of minutes between the times when VPOP3 collects mail using the AutoConnect feature.
NOTE. The use of Auto Connection can lead to the automatic timeout disconnection feature of dial-up networking or your modem not working, and therefore if you leave an Internet connection running for a long time, expecting it to disconnect after (say) 20 minutes of idle time, you may be disappointed (and get a big telephone bill).
If VPOP3 is collecting mail every 5 minutes, the RAS connection will never get chance to be idle for 20 minutes! If you want to use automatic disconnection, it is probably best to check the Auto Connect once per dial-up session box.
The Connect Through SOCKS Server box lets you specify that you want this Connection method to be via the SOCKS server specified on the Utilities -> Misc Settings Page.
The Use with main connection schedule box lets you indicate that this should be used when a simple schedule action is triggered.