On 7/31/2014 12:47 PM, Brian wrote: > On Thu 31 Jul 2014 at 10:52:39 -0400, Jerry Stuckle wrote: > >> On 7/31/2014 10:37 AM, Brian wrote: >>> >>> The reason for doing it given is generally along the lines of: >>> >>> Much of the current use of port 25 is by computers that have been >>> infected by malware and are sending spam without the knowledge of >>> the users of those computers. Port 587 improves security through >>> the use of required authentication and recommended TLS/SSL >>> encryption. >>> >>> What I do not understand is what prevents the malware (assuming it can >>> signicantly control the machine) from using the same authentication to >>> send spam as before. Isn't this back to square 1? >> >> Nothing, if the malware can get the userid and password. However, to do >> so you have to store the information on your machine. Additionally, the >> malware has to know which MUA you're using (to figure out where the >> userid and password are stored), and if your MUA has encrypted the >> information, how to decrypt it. > > One would expect the ISP's strategy to factor in the sophistication of > malware. which is presumably sophisticated enough to be able to use port > 25. >
Which is why many ISPs now block Port 25 from residential users. >> Not impossible, by any means. But much harder than just sending over >> port 25, which requires none of the above. > > The ISP's concern is (or should be) the customers who allow sending of > spam "without the knowledge of the users of those computers". These > same incompetent customers are now all going to start encrypting the > usernames and passwords used for sending email? > > Most MUAs can already encrypt the password (and sometimes the userid) if it is saved on the disk. Thunderbird does this, for instance. I assume Outlook does also, although I haven't checked it. I should add the malware would also have to know the MTA the userid/password are for. Again, not impossible by any means - but just one more thing the malware has to discover. For instance, I use my own mail server for most of my email; this account is used for non-business related stuff. Jerry -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: https://lists.debian.org/53da8e3f.1030...@attglobal.net