Sending messages

In order to send a message you first need to specify the recipients and the sender.

The list of distribution lists (defined in Manage lists) is shown in the Select distribution list field. Select one and the addresses in the list will be used as recipients. Each contact will receive a personal message.

The message sender will be specified in the Sender e-mail address and Sender name fields. You can freely type in these fields or select an address and a name from the comboboxes, which display the last 10 names and addresses previously used in sending operations (the lists will be empty if no message has ever been sent). If a subscription/unsubscription address was provided to the selected distribution list, it will be automatically shown as the message sender address. However this is just default behavior, the address and/or the name can be manually changed.
You can also optionally specify a Reply-To address: this is the address replies will be sent to. If it is left blank, replies will be sent to the sender address (this is the default behaviour for personal e-mail messages).

To send the message just click on the Send button. Obviously if it's the first sending operation, or if the connection settings have changed, it will be necessary to first set up the Send settings, otherwise the message won't be sent.

As an alternative to sending messages, it is possible to schedule the mailing operation, and let SendBlaster send it later automatically, at a given day and time, or even "park" the mailing operation to be manually launched later, in order to schedule a mailing operation, just click the Send later... button.

Two Send modes are available: Use SMTP server and Direct send.

     

Use direct send or the SMTP server?

The choice depends, first of all, on the availability of a good SMTP server. If your ISP SMTP server is able to handle many messages in fast sequence, or even sending more messages simultaneously, using an SMTP server is faster and more reliable, since your SMTP server is "closer" to your computer than the single recipient's e-mail server.

However, some providers, to prevent their users from using the server for spamming purposes, impose restrictions on the number of messages that can be sent within a specific time span and the number of messages that can be sent simultaneously (for instance, an SMTP server could accept no more than a message every 5 seconds and not allow sending more than 2 messages at a time). All messages that exceed these restrictions will be rejected with an error. This does not mean that the server or the software aren't working properly, but rather, that it will be necessary to set in a different way the sending timing option in the Advanced settings section.

In such cases, it could be faster and more convenient to use the direct send. The direct send requires a little more time to deliver each message (since it has to make a request to the DNS server and the e-mail server could be very "far" form the user's PC), however this time increase is compensated by the possibility to send more messages simultaneously without having to add extra pauses between messages.

Direct send is also useful when a sending operation has to be performed using a connection without knowing the SMTP server (typically the case when using a notebook "away", meaning not in the office or at home - common in the case of a public access wireless network).

     

The Advanced settings section allows you to fine-tune the sending timing, and other special settings. This is useful to perform a sending operation at the maximum possible speed allowed by the SMTP server antispam restrictions. Here's the meaning of each options:

Timing Tab

The right configuration cannot be set before a few attempts, verifying the number of messages that actually get delivered. To simplify the settings, some Suggested settings are available. They might not be optimized for your connection but can be considered a good starting point to get to the best configuration.

Warning: Distribution lists can contain invalid e-mail addresses, or some e-mail servers may be temporarily inactive. Therefore, when using lists that contain a great deal of addresses it should be considered normal and inevitable that, despite the chosen sending mode and the settings, not all messages get delivered and a certain percentage will return an error. In such case it will be possible to try to complete the sending operation at a later time using the history functions.

     

How can I get the right advanced settings?

To get the right advanced settings it's necessary to try out different combinations (normally a list with about 10 addresses will suffice) and verify how many messages actually get delivered (this info is given at the end of the sending operation, when it is also possible to check the logs). Users connected to a "tolerant" enough SMTP server won't probably experience many problems, regardless of the settings specified that will only effect the sending speed.
On the other hand, if your connection is to a rather "strict" STMP server, in order to be able to deliver a high number of messages it might be necessary to slow down message sending and avoid sending messages simultaneously.

Here's a few simple rules worth considering:

  • A tolerant SMTP server allows fast sending without pauses (or limited pauses anyway). On rather restricted SMTP servers that use numerous antispam filters, raise pauses and lower simultaneous connections.
  • Normally, SMTP servers don't allow sending many messages simultaneously, therefore when using the SMTP mode the number of connections must be low or, in certain situations, equal to 1 (no simultaneous connections). If the SMTP server is equipped with antispam restriction mechanisms, it may be necessary to slow down message sending by setting a pause of a few seconds between each send, and set a longer pause between message blocks. Also, blocks shouldn't contain more than a few dozen messages.
  • In case of a direct send, with a standard distribution list containing addresses belonging to different domains, the messages will be delivered to a variety of different servers: it is therefore possible to set a high number of connections* and limited (or none at all) pauses between messages and between blocks.
  • Raising the number of attempts in case of error can raise the percentage of success but it will slow down the sending operation, particularly if the number of simultaneous connections is low. Completing the operation at a later time from the history window (after having waited a few minutes) can be considered good practice.
     

Extra Tab

Additional Headers Tab

In some cases, advanced users may need to add custom headers to their message, used for performing special tasks (i.e. tracking, signing, etc). SendBlaster allows users to add up to ten headers to the message.


*In the Free edition the maximum number of connections is 2, even if a higher number is specified.