The 'Forward type' column allows you to specify how the message will be sent to the destination specified in the 'Forward to' column. The following types are available:
Redirect message', the default type, sends an exact copy of the message, leaving the original sender in the From address intact and unchanged, to the email address specified in the 'Forward to' field. If you just want to forward the message to another email account, this is probably what you want.
'Redirect summary' extracts the text of the message (ie, without any attachments or formatting) and sends a notification containing the first 160 characters to the email address specified in the 'Forward to' field. The From address of the summary message is the same as the From address in the original message.
''Redirect squeezed summary' is the same as 'Redirect summary,' except that it uses a compression algorithm to squeeze the text of the message down to a smaller size, while still allowing it to be read. If you would like a (technical) description of the compression algorithm, or to see an example of what compressed text may look like, see the DESCRIPTION section of this page.
'Forward summary' is similar to 'Redirect summary', but the From address used on the notification email is your default personality. The subject will be modified to include the sender of the original message.
'Forward squeezed summary' is the same as 'Forward summary', but using the same compression as 'Redirect squeezed summary.'
'Notification only' means email is sent to the 'Forward to' address with a message body that says only that a new email has arrived, and provides the From address of the new email.
'SMS summary' is like 'Forward summary' but assumes that the 'Forward to' column will contain a full mobile telephone number (including country code) instead of an email address. It then sends the notification to that phone via SMS. As with all SMS messages, the originator is the Mobile Number of the default personality for the account.
'SMS squeezed summary' is like 'Forward squeezed summary' but, again, expects a mobile telephone number in the 'Forward to' column.
'SMS subject' sends an SMS message containing only the first 160 characters of the subject of the triggering email. The 'Forward to' column must be a full mobile telephone number (including country code).
'Custom' directly inserts the text in the "Forward to" field into the sieve script. This means you need to include the notify command and all parameters you plan to pass to it. See the sieve documentation for more information. Some examples:
notify :method "mailto" :options ["firstname.lastname@example.org","From","Orig"] :message "$from$ / $subject$ / $text$"
notify :method "sms" :options ["123456789","Squeeze","High"] :message "$from$ / $subject$ / $text$"
If you are using either 'SMS summary', 'SMS squeezed summary' or 'SMS subject', ensure that the 'Forward to' column contains a mobile telephone number. You must include the country and area code in the number, and you will need to have purchased enough SMS Credits to pay for the SMS messages that will be sent. For more information on purchasing SMS Credits, see Paying for SMS messages.
An alias target is just the email address (or addresses) to actually send the email to that matches that alias.
By default, the target of all aliases is your account name, so email sent to an alias instead is sent to your account.
You can, however, change the target of an alias to be any other account, including other FastMail accounts or a completely external email address.
You can target multiple accounts by putting a comma (,) separated list of email addresses. If you do that, a copy of each email will be delivered to each target address. This can be a useful way to direct a copy of all email to a separate backup account at another provider if you want. To do that, create an account and setup an alias that targets both your account, and the external account you want backups to go to. Then when you tell people about your email address, tell them your alias address, never your accounts address.
You can also change targets to use plus addressing. Commonly, you might want email sent to a particular alias to go into a certain folder. The easiest way to do this is to use plus addressing with the 'Target'. So if you have a folder 'aliasmessages', you can set the target to 'email@example.com', and any email sent to the alias will automatically be put in the 'aliasmessages' folder.
One thing to note is that alias targeting occurs before any rules or spam scanning is applied to a message.