 | Chris Owen
is President and founder of Hubris Communications. Until the opening of Hubris' Wichita office, Mr. Owen was the sole network technician and systems administrator of the company. Hubris Communications is a provider of premium Dial-Up, ADSL, SDSL, Wireless, and dedicated Internet Services. Founded in Garden City, Kansas and doing business since July 1995, Hubris Communications, Inc. serves over 3,200 customers in south central and southwestern Kansas. Chris can be reach at (316) 858-3000 or owenc@hubris.net |
Computers & Software
2003-08-01 11:28:00
FTP or e-mail?
QUESTION: What is the difference between sending files via FTP and via email?
ANSWER: The first one is the right way and the second one is the wrong way ;-] Seriously, sending files via email should really be limited to smaller files as the protocol that email uses is not really designed for moving very large amounts of data. One real problem is that with email there are really two different protocols at work. Sending email is usually done with using the Simple Mail Transport Protocol (SMTP). Because email is primarily a text based application, most SMTP email is also converted to text before it is sent. This increases the size of binary files by approximately 30%. There may be more than one of these SMTP transactions as the email is sent. Each of these "hops" means the file must be processed an additional time. The protocol used to pick up email once that email is on the other end though is quite different than SMTP. Usually email is picked up via Post Office Protocol (POP), which works quite differently from SMTP. With POP, the person's entire mailbox contents normally have to be loaded into memory when they check their mail. In order to do this, an index of the mailbox must be built. This requires scanning the complete contents of the mailbox to find out where messages start and stop and perhaps doing other intensive types of scanning. This means that picking up mail is actually much harder than sending it. Because of this we often see customers who have so much mail in their mailbox they may have problems opening it. In addition to these problems, the modern process of handling email also has introduced other problems with very large emails. We for instance scan all incoming emails for viruses. This means breaking down each email into its component parts, uncompressing compressed components and scanning all the contents. We also scan all messages for their SPAM (junk mail) content and mark the messages according (so the customer can filter out messages they don't want automatically). All this added scanning and processing of email messages makes sending very large files even more of a disadvantage. File Transfer Protocol (FTP) on the other hand, is specifically designed to move large files. With FTP the file is only moved once and is usually done as binary data (no conversion to text). FTP has very little overhead and usually very little processing is done to the file. Because of this, FTP is far more efficient. FTP does require a separate FTP client though and a FTP server on which to place the files but if you are planning on moving large amounts of data it is definitely the way to go. Generally, we recommend that you not send files larger than about 5MB via email. If the person on the other end may be using dialup access you should limit your file size to probably less than 1MB. Most Internet Service providers will generally limit the size of emails they will receive (usually in the 5MB to 20MB range) so anything larger may not even be possible.
