MTA and bcc field

[samuelsancho]

Hi, I've a doubt about how any MTA see the messages with a lot of bcc. If you send an email with 20 emails to differents domains in bcc fields, all the destinations MTA can see all directions in bcc field? or the MTA only see the directions in bcc who goes to his own domain?.

Thank you in advance.

Samuel

[Tze Tai Mak · Accepted solution]

The sending MTA will only send recipients destinating to MX gateway of that domain.

For example, mail client sends a email from user_a@a.com, to user_b1@b.com, and bcc user_b2@b.com and user_c1@c.com

From sending MTA of a.com to MX gateway of b.com

MAIL FROM: user_a@a.com

RCPT TO: user_b1@b.com

RCPT TO: user_b2@b.com

DATA

From: user_a@a.com

To: user_b1@b.com

Content

.

From sending MTA of a.com to MX gateway of c.com

MAIL FROM: user_a@a.com

RCPT TO: user_c1@c.com

DATA

From: user_a@a.com

To:  user_b1@b.com

Content

.