Rudi Ahlers wrote:
>
>>> A client of ours just requested to increase the max_recipients in Exim
>>> to 300, since he keeps getting "554 Too many recipients" error when
>>> sending a marketing email from MS Outlook.
>>>
>>> I would like to know, what are the implications of increasing the
>>> default 100 to 300? If 300 email recipients were added to the "To:"
>>> field, does it establish 300 connections to the SMTP server, or not?
>> Locally between Outlook and Exim, no, this won't establish more than
>> one connection to the SMTP server. If Exim is acting as a smart
>> relay, it'll get one copy of the message with the whole list of
>> addresses in one transaction.
>>
>> On the "other side" between Exim and the eventual recipients of this
>> mail, the likelihood is that Exim will make one or two connections per
>> destination domain. If all 200+ recipients are at the same domain
>> (say, all yahoo.com addresses) then Exim may run into problems, but
>> it's not very likely.
>>
>> However, if that list grows very much larger, both you and your client
>> are going to be a lot happier if the client stops attempting to send
>> out his own marketing mail with Outlook and instead engages a
>> reputable email service provider. Assuming, that is, that he has
>> appropriately confirmed permission to send email to all those people.
>
> Thanx Bart, this explains a lot :)
>
> So, as I have feared, I could run into problems with being blacklisted
> by other mail server then. The client does has legit email addresses,
"Legit" in this context seems to be a matter of opinion and eventually someone
who signed up for this service is likely to forget it and report it as spam to
one or more of the blacklisting services. When this happens it is extremely
painful and time-consuming to convince whoever runs the services to take you off
the lists, and meanwhile any site using those blacklists will discard all of
your email. You'll probably have to prove that all mail to groups has a request
confirmation to establish that the sign-up address is valid and a link at the
bottom of each email to request removal from the list.
> and wants to use Outlook (not everyone can use Linux ;)) since it
> embeds the images, instead of linking to it on the internet.
>
> The exim server in question is a hosting mail server, i.e. it's a mail
> server, and not a smart relay.
>
> I'll see if I can convince the client to use an alternative method of
> doing this.
A mail list will work, or even an alias that the person in charge of the list
can maintain, but it is really better to outsource it to someone who knows how
to deal with the blacklist sites.
--
Les Mikesell
lesmikesell at gmail.com