Unclear on argument passing to "sendmail'

[John Draper]

I will respond to part of this, although it wasn't directed to me.

Tim Williams wrote:

> However it really depends on the use-case,   relaying through another
> server will give you no control over bad addresses,  you have to wait
> for bounces from the recipient's server,  or conversely the ISP server
> can give fails 4xx & 5xx for valid addresses.   The ISP may only
> accept email addressed from their local domains, and you may be
> breaking their TOCs or AUP and get blocked.

I usually will have no problem with this,  and for one reason is because
before I add a new ISP to my spam reporting queue, I establish a
direct SMTP connection with the ISP's "abuse" email server to confirm
the Email is good.  I get a lot more then my share of BAD or Bogus Emails
listed in some of these whois queries I get.

>
> On the flip side, some ISPs block outbound port 25 except through
> their servers, or transparent proxy port 25,  so Direct MX is
> unusable.

I send all of my spam reports through a commercial T1 link..  I made
the bad mistake of sending my spam reports directly from my ComCrap
(err - comcast) account, and my service got hosed for a day or so.

>> Hmmm - the problem I have is if I knowingly
>> put in a bad recipient,  and try to send to a
>> unknown user,  I get all appearances that
>> the mail went through.
>
>
> Yes this will happen if you use a relay server.

yea - I know....  :-(

>
>> Ok,   so If I already have a MX hostname
>> of "mail.myhost.com",  then I would put
>> into my "to_email"...    <myusername>@myhost.com for
>
>
> Yes,  if you just used username the server wouldn't know which domain
> the email was being sent to and therefore how to route it.
>
>> By the way,  I'm sending this mail to a "sms"
>> gateway to a cellular provider, so the
>> username is their phone number.
>
>
> If you only ever send to this gateway then you might as well try MX
> records, you will have more control,  but you will need to manage
> queueing yourself for temporary failures,  or you may decide that if
> you get a temporary failure (4xx) to just fire the email off to your
> ISP server and let them deal with it.

I'm currently exploring a number of different options at this time,
including giving the customer an option to go back and re-visit their
order page and get an update in the event the message bounces.

I'm setting up a special "reply_to" address which I use to collect
bounces, and customer's asknowledgement they got the content.
Once I get the Ack from the customer,  I'll KNOW they got the product.

>
>
>> But
>> (sigh),  these providers don't appear
>> to tell me if I put in a bogus phone number.
>
>
> Unfortunately not all mail servers will fail an invalid address even
> if they aren't relaying the email.   

I haven't really run into a lot of them,  but I've had NO experience with
SMTP->SMS gateways.

> But in this case the SMS
> "gateway" is probably relaying to a backend system for the SMSc and
> will accept any address with a valid domain part. 

I already know that Sprint does this,  but (sigh) I don't even get the 
bounces if
I re-direct them to a specific Email box....  DARN - Foiled again.

John