Bulk Email Speed Test Results

We only describe here the results of bulk email speed test that we have conducted with AY Mail 2 Corporate Edition software. These results are obtained with a fast no-delay SMTP server software, and do not represent a real world situation where server software will almost certainly cause delays and lower the transmission speed. For the interpretation of the results, see Bulk Email Speed where we explain how these results may be applied to the real world.

The goal of the test was to measure how fast the bulk mail software can transfer messages to the server. The test does not measure the time required for actual delivery.

Bulk Email Software

We have used AY Mail 2 Corporate Edition, which can send bulk email in three modes:

Personalized mode where each message is individual for each recipient and must be transmitted separately. Even though this mode is slow, it is capable of producing highly personalized messages.

Bulk mode where one message is sent to all the recipients, which means that the text of the message needs to be transferred only once. To increase reliability, AY Mail sends in chunks of 1,000 recipients.

Turbo mode is specific to AY Mail. It is the same as bulk mode, but boosts up the transfer speed. Since this does not strictly conform to the SMTP protocol, it doesn't work for all SMTP servers, but most of the servers work fine.

Server Software

We have used specially designed fast no-delay SMTP server, which just accepts messages and doesn't do any checking on the connections or addresses that it receives from the bulk email software. That is how the SMTP server should behave. Unfortunately, real world servers usually run checks on connecting computers and verify addresses, and therefore will cause delays.

The server was configured to destroy all incoming e-mail, so nothing has been actually send outside of our laboratory.

The Computers

We have used three different computers in our test:

Slow computer - PIII-550MHz 128MB Windows XP
Fast computer - P4-2GHz 480MB Windows XP
Remote computer - PIII-466MHz 128MB Windows NT 4.0

The Connections

We have used three different network connections:

Local connection where the server software were installed on the same computer as the bulk email software. Similar results could be obtained in Gigabit network.

Ethernet connection where the server software were installed on the Remote computer and connected to the computer running the bulk email software through 10Mb Ethernet.

Modem connection where the server software were installed on the Remote computer and connected to the computer running the bulk email software through modem line with estimated connection speed of 20Kb.

The Message

We have used a real message sent to us by Amazon.com advertising a new Harry Potter book. The size of the message was 5.2K.

We measured the time used by bulk email software to transfer 100,000 messages to the server. With modem connection, it would take too much time, so we made a test with 1,000 messages. For each test, we calculated the time necessary to transfer 1,000 messages and the number of messages that could be sent in one hour.

The Results

The table below presents the measured speed of the bulk email:

These are the same data presented as a number of emails that can be sent per hour:

These numbers are obtained with a special SMTP server which causes no transmission delays. How to apply these results to the real world emailing? See Bulk Email Speed.