[Info-vax] SMTP chunk sizes

[Stephen Hoffman]

On 2015-03-23 16:32:01 +0000, Rich Jordan said:

>      the MS size limit is 25MB; the files being sent are smaller but 
> hit the connection time limit.
> 
>      The firewall indicate the packets going out were
> 
>      The ISP provided relay host is 'always busy, retry later', meaning 
> I think its greylisting the MTAs that use it, which VMS also doesn't 
> like.

Greylisting is typically skipped after some specified number of 
successful messages received after retry, or the whitelisting can be 
manually configured.  VMS works fine with a greylisting server.   That 
the ISP server is always busy means something else, such as the need to 
relay via a submission port for the particular mail server, or 
potentially a configuration error somewhere.  The TCP/IP Services SMTP 
server lacks the submission port relay capability, though IIRC Process 
had (has?) an add-on which allowed something like that.   Postfix and 
most other current servers do have the ability to use an authenticated 
relay via the submission port.   TCP/IP Services SMTP has many issues 
in a modern network.  I almost always gateway through a local Postfix 
server or equivalent, and generally avoid configuring OpenVMS with 
TCP/IP Services to send directly.

> Thought about getting hte community edition of Communigate Pro in place 
> but for now we're stuck with the hardware/resources we have which means 
> probably using MS IIS SMTP stack for the smarthost.  Its in test now.

Using a relay (gateway) through an existing Exchange Server usually works.

Lamson is Python, and might be convinced to work on OpenVMS, if one of 
the Process stacks is not an option.


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