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problems in sending mail using telnet ( SMTP server)

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manishparab
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PostPosted: Thu Feb 02, 2006 6:14 am    Post subject: problems in sending mail using telnet ( SMTP server) Reply with quote

hi i,m manish , i want to send mail using smtp , for that i use telnet and i try to connect the list servers which i found on net like
( Microsoft telnet > o mit.edu 25), but every-time i try to connect to any of the server,either the telnet is failing to connect to the sever or the it gives the message that the software running on the host machine has boken the established connection.

i don't know what's going wrong, plz tell me the way to do it, also the servers which allow to send such mails.
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AdamV
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PostPosted: Thu Feb 02, 2006 2:39 pm    Post subject: Reply with quote

any normally configured (to RFC) SMTP mail server should allow this to work except if has been secured to only accept connections (and therefore mail) from a particular set of hosts / domains / IP ranges.
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moondoggie
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PostPosted: Thu Feb 02, 2006 4:39 pm    Post subject: Reply with quote

yes, the poster formerly known as eliza is correct. what you are asking for is called an "open relay" smtp server, and it is frowned upon using them this way because spammers use open relay servers to send out spam. the vast majority of smtp servers out there will not allow you to send mail through them if you are not connected to their lan/wan.
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AdamV
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PostPosted: Thu Feb 02, 2006 6:49 pm    Post subject: Reply with quote

moondoggie wrote:
yes, the poster formerly known as eliza is correct. what you are asking for is called an "open relay" smtp server, and it is frowned upon using them this way because spammers use open relay servers to send out spam. the vast majority of smtp servers out there will not allow you to send mail through them if you are not connected to their lan/wan.

not strictly correct - you should be able to send mail to a server from the outside world, and this would not be classed as an open relay. Using a telnet client over port 25 to do this ought to work and is a legitimate test.

Manish,
Is it possible you are trying to do this to a server other than a mailserver?

Is it possible your own network firewall is blocking this (by blocking port 25 except from your known mailservers you prevent email worms on other machines from sending using their own SMTP engines if you do get infected, which makes you a slightly better "net citizen")
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manishparab
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PostPosted: Mon Feb 13, 2006 6:15 pm    Post subject: so i cant send the mail Reply with quote

so dose that all mean i cant send the mail using SMTP.
plz help me in this, i ,m very much curious abt it.

Sad
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White Scorpion
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PostPosted: Mon Feb 13, 2006 7:37 pm    Post subject: Reply with quote

you should try netcat instead of telnet. Microsofts telnet often gives people connection problems. With netcat you can also use the backspace button if you made a mistake.

read this for more info once your connected.
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manishparab
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PostPosted: Tue Feb 14, 2006 7:17 am    Post subject: netcat is also not working Reply with quote

hi tryed netcat but still it not working, i dont know whats wrong, i think the severs which i,m using to send mails are not proper, can some one give me atlest one server which allows me to send such mails.

plz i,m not getting this frm past 15 days, i ,m very keen to know abt this Sad
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White Scorpion
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PostPosted: Tue Feb 14, 2006 10:04 pm    Post subject: Reply with quote

What exactly is happening then? Could you show a screenshot?

if you go to the cmd.exe and type nslookup and hit <enter>. you come in the nslookup program. There type:

set type=mx and hit <enter>

Finally type in a domain of your choosing. Let's say security-forums.com.

The result will be the mailserver(s) used for that domain.

next type in the cmd.exe nc <mailserver> 25 and hit <enter>. Now you should be connected to the mailserver and able to communicate with it.

If this doesn't work then please let us know exactly what is happening.
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morongo
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PostPosted: Sat Aug 19, 2006 7:54 am    Post subject: Reply with quote

manishparab, try connecting to another host (or several) using port-25...if telnet just times-out, you're ISP probably has port-25 blocked.

Most of the major ISPs have moved to this for the reasons given in the posts above.

For end-users, this is usually not a problem because they use the provider's email services or webmail, anyway.

However, if you're a webmaster and have your own domain, this keeps you from using you own mail services unless you install webmail on your website or use a 'relay'.

The bad part of using 3rd party smtp connections is that they *also* attach a 'relay header' which can result in your mail being consigned to 'junk' status or not delivered at all.

The only option you have then, is to publish an SPF in your servers DNS records (which you should probably do regardless).

But anyway, if you can't get out on port-25 to anybody, you most likely have a block on that port...who's your provider?
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soniag
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PostPosted: Tue Feb 13, 2007 1:46 pm    Post subject: Reply with quote

Hi,

I was trying to connect to yahoo/google mail server using telnet and I have a few doubts. They are basic queries and it would be great if someone can help me with them.

1. I cannot connect to port 25. The reason I found on various posts and websites was that the servers avoided spamming this way. However, when I went to Yahoo help, it says that the SMTP port on the server is 465. If this has to be anyway declared publicly, how is the protection provided against spamming? There are various hurdles like usage of ssl and mandatory authentication etc., but couldn't these be provided on port 25 itself? That would prevent spamming, wouldn't it?

2. If I send a mail from xyz@gmail.com to abc@yahoo.com, the mail is first received by the gmail server which acts as an open relay and forwards this mail to yahoo mail server. Is gmail server
pre-configured to send mail to yahoo smtp server at port 465? or if yahoo smtp server receives a mail from gmail server on port 25, it won't discard it, probably because gmail server is in the list of 'servers/hosts' allowed to interact with the yahoo smtp server ?

The more I think, the more confusing it gets. Please help!!

Thanks,
Sonia
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morongo
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PostPosted: Fri Feb 16, 2007 5:24 am    Post subject: Reply with quote

As stated above, end users don't have a problem with port-25 blocking but any of us who run websites are rather more inconvenienced because we can't directly access our (own) mail servers and are forced to resort to webmail, or a relay/proxy of some sort.

It's also true when using relays that our headers indicate that the mail has been relayed and that could very well lead to the recipient's server delegating our mail to either spam or junk status.

However, I've found an absolutely elegant solution that has eliminated my Verizon port-25 block and now my email access has been completely restored. I can send on port-25 from any email client directly to my server, no relay headers, no proxy, no webmail.

Op25 from Wing Network Technology...I got on their beta program, maybe you can too.
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davesecurity
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PostPosted: Sun Feb 18, 2007 9:15 pm    Post subject: Your Internet Host Provider Might Have Blocked port 25 Reply with quote

Most of the internet service providers are blocking port 25, since it culd be exploited by some loop in your computer securuty.

contact your ISP provider to make sure that your port 25 is not blocked.

david
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mazzel vedder
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PostPosted: Wed Mar 14, 2007 12:54 pm    Post subject: Delayed problem when sending email Reply with quote

Hi all,

I'm using Yahoo Small Business for web hosting and e-mail server. And now I have a problem with sending an email. My email that I've tried to send is less than 100 Kbps. But it will take a long time for sending.

I'm sure if my ISP is not blocked port 25. Because it still sending. It's just about time delay.

Here, I show you my network statistic (I think it would be help you to analyze this problem) :

Download speed : 623 Kbps
Upload speed : 32.3 Kbps
Average time when I pinging the smtp server is : 395 (and no packet loss)

What can I do to resolve this problem?

Thank you,
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