Check string(line) in a file and send email
The else-pass construct is unnecessary. The else clause is not required. Leaving it of has the same result as what you have now.



You loop over the same file twice. Instead you can check the line for both messages in the same loop.

for line in open("status.txt"):
    if "Slave_IO_Running: Yes" in line or "Slave_SQL_Running: Yes" in line2:
        print "match",line
        i=i+1




However, the above change points out a potential bug. We don't have any information about what the contents of status.txt are. If it is possible for either of those strings to appear more than once, the code as posted (and my above update) could find two matches without finding a result for IO and SQL.
1

sql_found = false
io_found = false
for line in open("status.txt"):
    if not io_found and "Slave_IO_Running: Yes" in line:
        print "match",line
        io_found = true
    if not sql_found and "Slave_SQL_Running: Yes" in line:
        print "match",line
        sql_found = true

if not sql_found or not io_found:
    # send email




If the status file is long, you can break out of the loop after both lines have been found. This would prevent unnecessary work when you already know the correct information.



i is not a good variable name. It does not convey any information about how it is being used. In addition, i is widely accepted as the variable name for indexing in a loop. In this code you are looping, but i is being used for something else. Changing the name will prevent any confusion.



You can use the with construct to ensure the file is closed when you are done with it.

with open(status) as f:
    for line in open("status.txt"):
        # operate on a line


This is a short running script, so it is not a huge deal, but it is a good practice to get into when you move to writing longer applications.
While this is a short running 



You never use sys, os or email.Utils. These imports can be removed.



1: If we extrapolate on the idea that the line might show up more than once, that could also mean that the file could contain a Yes line followed by a No line. If this is the case, this simple loop logic would no longer be sufficient.