Optimal number of threads

AY Mail 2. Any Edition
No special skills required

If you send direct, AY Mail is capable of sending multiple messages at a time. Each sending process is called a thread. You can have up to 256 threads, but it is not always optimal to use all 256 available threads.

If you send your mail through AY Track, you can configure AY Track to use up to 512 threads but usually you need much less.

If you use too many threads, the transmission speed and success rate will drop dramatically.

Generally we recommend that you use the following number of threads, which are likely to produce the best performance.

Dial-up connections - 1-2
DSL or Cable connections - 5-8
T1 or better connections - 15-20

These numbers are likely to ensure the fastest transfer of your messages.

If you have time and really want to optimize the number of threads you use, the information below may help you:

At any moment, a thread may be in one of the three conditions:

Transmitting something to the server
Receiving something from the server
Waiting for the server response

When all the threads are waiting, you are losing time because it would be possible to send more messages. Therefore, if you use too few threads, the speed is low.

When several threads are transmitting or receiving something at the same time they compete with each other for bandwidth and interfere with each other. This may lead to connection breaks, so some of the threads may be aborted prematurely. Therefore, if you use too many threads the speed drops dramatically.

Generally, if you send short messages, mailing threads will spend most of the time waiting, so you should increase the number of threads. If you send long messages, then most of the time they will be transmitting the message body, so you should decrease the number of threads.

If you have a fast connection, you can allow more threads to run at the same time even if they're all transmitting. With a slow, dial up connection you should not have more than one or two threads transmitting at the same time.

So, if you send big files over a modem connection, the best number of threads would be one (rarely two).

If you send very small messages over a fast Internet connection, the optimum number can be up to 50 threads.

Your situation is probably somewhere in between and you can select the best number of threads by experimenting.

If you send relatively short messages using direct send, the load may be very uneven. Sometimes, you will have many threads waiting for a slow server, in which case it would be beneficial to increase the number of threads. Other times, you may have several threads transmitting to very active servers and interfering with each other. It is hard to find a good number of threads for such situations.

If you send through AY Track, you can even the load by limiting the number of messages that you can send per second. For a very fast Internet connection you can, for example, specify 100 threads, and limit the sending speed to 20 messages per second. In this situation, AY Track will not create threads at a rate more than 20 per second, which prevents high load for the situations when threads are very active. However, when many threads are waiting, AY Mail will still create new threads at a rate of 20 per second, and waiting threads will not affect the performance.

If you have a slower connection you can still use 100 threads, but use a limit of 5 or 1 per second. You cannot use this method with very slow connections, such as dial-up, because even 5-7 threads working together are capable of totally blocking each other or even causing modem disconnect.

To specify the number of threads for AY Mail, select Settings->Mail Sending from the main menu to open the Mail Sending Settings dialog.

To specify a number of threads and sending speed for AY Track select Settings->AY Track->Mail Sending from the main menu and click on the Timing button to open AY Track Timing Parameters dialog.