Hello,

So, I'm not even sure if this will be possible for me to do (then again, that's why I'm asking for help )

What I'm trying to do is pull multiple lines out of a very large text file, separating them into smaller files. Basically it's a text archive of a few hundred emails.

What I have to work with is I do have a constant start line and end line. What I've been doing so far is to grep for the start of a message (grepping for '^From:' While this will pull the one line I am unsure as to how I can then get the next x number of lines to record into some sort of new text file and then stop at the known end line. (at the moment it's 30 '+' symbols...I don't know why, that's how it came)

I'm thinking grep probably won't do all I want it to do. Should I be looking for something more along the lines of sed or awk?

Not sure how your file exactly looks like but the following awk command should be a good start.
It searches for a pattern and prints the lines until a line begins with "++++":

awk '
/^From:/{found=1}
found && $1 ~ /^++++/ {found=0}
found {print}' file

here's a simular way to do also:

awk '
/^From:/ { f ; next }
f { print }
/+++$/ { f = "" ; next }' file