When I try to send an email with a large amount of atatchments varying in size of the Mega Byte rage. I will recieve a error 552 from my mail server. I looked this error message up and found a refernce to it in both RFC 821 and 788 section 4.5.3 Sizes

Acording to RFC 821 there are size limits on user, domain, path...

And if these limits are exceeded you may recieve one of the folowing:

500 Line too long.
501 Path too long
552 Too many recipients.
552 Too much mail data.

My question is:

Is these limits spasific to the individual mail server you are useing or are they universal limits?