Outlook - Log on to incoming mail server before sending email

I have SMTP (Outgoing email) for Optonline, but in advanced settings where it asks for logon I just use the same settings as incoming mail server, which I assume is the same logon and it works for me.

"Why would anyone select that option?"

Quite a while ago, you could send without any sort of authentication.  This lead to all sorts of problems with people spamming through someone else's email server.

One of the solutions for this was to require that you log into the POP server before sending email.  You'd have a limited amount of time (1 minute?) during which you could send email.

I think this setting is rarely ever used anymore.  As mentioned above, "Same settings..." is pretty common.  This has your client providing credentials to the SMTP server regardless of what it uses to receive email.

I am aware of what most people use as a setting and am also aware then the "log on to incoming mail server before sending email" isn't used much but.... that is not the question. I am trying to find out, in more detail, what happens when you select that setting. Specifically "I was told if that option is selected that you would only be able to send to recipients on the same domain as the incoming server. Is that correct?"

I don't believe that is correct.

I believe it gives you authority to send for a limited period of time without regard to whom you are sending.

SMTP protocol for PO3 and IMAP accounts require that access to the SMTP server be "authenticated" in order to be able to send any emails using that server. For the majority of users that means using the same log in credentials as used for the incoming (POP3 or IMAP) server. The next import element is the PORT used. Generally, if Port 25 is used, the restriction is that you would not be able to access that server "outside" of the service area of your email service provider  typically your internet service provider in this instance - (a function otherwise referred to as "relaying"),. The restriction is not to whom you can send emails but rather gaining access to the SMTP server altogether.

A classic example would be a scenario where you travel outside your ISP's service area and try to send emails using PORT 25. In this case, you would need to change the SMTP server settings and use the credentials for another SMTP server. (most settings now use Ports 465 or 587 allowing access from anywhere regardless of what ISP is being used to access the Internet).

For more info then you'll probably want to know about email protocols - you can follow the various links starting with this article

SMTP Authentication
https://en.wikipedia.org/wiki/SMTP_Authentication

For the record, SMTP authentication for POP3/Imap accounts is nothing specific to Outlook - it is part of the industry standard POP3/IMap mail protocol applicable to any email client in use.

Hi,
I totally agree with Jackie Man that SMTP authentication setting can be same as Incoming server setting but in personal domain, the administrator has permission to set the authority on whether you can send emails outside the domain or not.
If you need further clarification on POP or SMTP settings then visits
https://support.office.com/en-us/article/POP-and-IMAP-settings-for-Outlook-Office-365-for-business-7fc677eb-2491-4cbc-8153-8e7113525f6c
Hope this will rectify your doubt.
Thanks & Regards
Christ

I have to chuckle a little. The question wasn't "what kind of SMTP authentication should I choose". The question was about the specific choice  "Log on to incoming mail server before sending email" and how it would effect sending email. Specifically if it would limit sending to recipients on one domain.

   Trying to sift through the above I get the impression there are two answers:

1) That the answer is "it is all up to the administrator of the smtp server. He/she can decide if sending will be limited
    to the one domain or many".
2) The option has nothing to do with recipients on different domains. You can send to many domains. That option will
    just open the send window for a specific period of time.

Correct?

Answer 1 is correct.  I wasn't as thorough when I posted my original response.  My experience in the rare times when I've had to use that method is that any recipient was acceptable.  As Jackie Man pointed out, the admin can make such a restriction.  On the other hand, that goes for other authentication methods also.

I'm not sure of the origin of the question.  I've not seen this sort of authentication required for quite a while.

You'll laugh at the origin of the question. Acronis and the way they think. Their cloud backup solution doesn't email. Their tech looked at my email settings and said "There is the problem. You are emailing to recipients on different domains.". My jaw dropped. I immediately asked for a tier two tech to explain why that was a problem.  

The tier two tech said "The first tech assumed (without looking) that I had the "Log on to incoming mail server before sending email" checked. I didn't.

Since the tier one tech was so ignorant I decided to see if the tier two tech was accurate in his comment that you can't send to different domains with that option was checked. Hence the question.

With Acronis it takes a month and tier 99 access just to fine someone that understands email. Not their backup product. Just email. Been dealing with them 15 years and still haven't found anyone who know their backup product :)