advice needed about "554 Too many recipients"

[SoftDux]

Hi all,

A client of ours just requested to increase the max_recipients in Exim to 300, since he keeps getting "554 Too many recipients" error when sending a marketing email from MS Outlook.

Before you tell me to use Pine / Mutt / etc to send plain-text emails via mailman, this isn't an option.

I would like to know, what are the implications of increasing the default 100 to 300? If 300 email recipients were added to the "To:" field, does it establish 300 connections to the SMTP server, or not?

In the Exim documentation (14.Â****Main configuration) I found this:

"If this option is set greater than zero, it specifies the maximum number of original recipients for any message. Additional recipients that are generated by aliasing or forwarding do not count. SMTP messages get a 452 response for all recipients over the limit; earlier recipients are delivered as normal. Non-SMTP messages with too many recipients are failed, and no deliveries are done.

Note: The RFCs specify that an SMTP server should accept at least 100 RCPT commands in a single message."


But, this doesn't tell me if it will have a performance issue with the server, or if other mail servers will have problems with our mail server sending the email to so many recipients in one go.

Can someone give me some pointers on this one?

[Infopro]

...
Before you tell me to use Pine / Mutt / etc to send plain-text emails via mailman, this isn't an option.

I guess sending BCC isn't an option either?