Question : Understanding MIME

Hi

I am trying to get my head around MIME, but it's not working :(

From what I understand (and I've read the RFC's) etc - MIME is a way to, amongst others, send attachments in SMTP mail.

So, let's say I want to send my friend a picture of a castle in JPEG.

Would the SMTP conversation go like this;

MAIL FROM: [email protected]
RCPT TO: [email protected]
DATA
From: [email protected]
To: [email protected]
Subject: Picture of castle

MIME-Version: 1.0
Content-Type: multipart/alternative;

Image/Jpeg
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Hi - here is a picture of a castle

.

??

So, basically, all the apparently random characters I wrote are a way for the receiving SMTP server to compose the attachment on the other side?

Am I vaguely correct here? ;)

Answer : Understanding MIME

well MIME encoding is known to have a lot of overhead

"the actual length of MIME-compliant base64-encoded binary data is usually about 137% of the original data length, though for very short messages the overhead can be a lot higher because of the overhead of the headers. Very roughly, the final size of base64-encoded binary data is equal to 1.37 times the original data size + 814 bytes (for headers)."

http://en.wikipedia.org/wiki/Base64#MIME