use or

Do I use or to send emails from my third party application?
I have SBS server and exchange is working as it should, we use a third party application which sends emails to clients with a PDF invoice.  There are no notes.
If I use smtp and port: 587 the emails work but if I use smtp port 25 it does not work.  Port 25 is open.
Should I be using port 25?
Apologies if its a dumb question.
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WORKS2011Austin Tech CompanyCommented:
Should I be using port 25?
no, not if the application is working using port 587. Some IPS's block 25 for sending email to fight spam, it uses port 587 so your ISP doesn't think the third party app is a spam relay.

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I QasmiTechnical LeadCommented: port 25 and 587 both are used for mailflow

port 587 is used in case you have a smarthost for mailflow / or for security reasons

and if your application is working  on 587 its fine, let it work on 587
If the mail is going from  third party application ans it's working then keep opn using port 587 as it secure.
ScorpioManAuthor Commented:
thanks for the quick response
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