mail sending method

[chief]

What is the best setting for the following?

What determines the setting that is used?

nternal PHP mail() (delayed to prevent timeouts)  (xxx ms) per email and  (xxx mins) every  xxx emails.

[DW]

If you are using SMTP which is recommended you don't need to worry about this setting.  Internal PHP mail is more unpredictable than SMTP and takes up more system resources.  (A new program runs on the server for -each- message)  I would advise sending about 1 email every two seconds at the very most, so "2000" ms per email and "0" mins every "X" emails.

Regards

[chief]

Doesn't SMTP use the local connection of the ISP.
Would the ISP object to doing mass mailing thru the SMTP, therefore PHP is a better choice to avoid ISP complaint issues?

[DW]

Your ISP (home or work internet service provider) is unlikely to allow sending of commercial email.  For this reason ListMail should generally not be installed on your home or work computer.

Certain web hosts do allow sending of commercial list email to a limit.  Some of those hosts are mentioned here. Beyond their limit (with ThirdSphere it's 25,000 per day for $25/mo) shared hosting is not a good choice and it is recommended to obtain a dedicated server for about ~$70/mo with a hosting control panel (Plesk is recommended).

ListMail's SMTP method of sending is far more efficient for a web host to handle than messages sent with PHP mail.  A good host with a fair email policy should have no problems allowing the use of their SMTP server as long as you act within their limits.

I have only heard of one host in several years that has recommended PHP mail over SMTP for list email.  

If you currently have a shared hosting package that can be expected to allow list email I recommend contacting them for exact details about what their limits are.

Regards