MCSendMail locks up

In my custom application, written on NetOS 6.3, MCSendMail works well for most of my customers. Recently, however, Verizon customers with FIOS and an ActionTec MI-424-WR router are having problems. It seems the call to MCSendMail locks up and never returns. This, after calling MCSetSmtpAuthentication.

Replace the ActionTec router with a Linksys or D-Link and it works fine. Outlook, Eudora, etc all work fine with the ActionTec router. It’s just the combo of ActionTec and the ConnectME that fails.

No other customers experience this. They have Verizon DSL on copper, Comcast, Qwest, Embarq, etc - all the usual ISPs, and they all work fine.

Anyone else observed similar issues? Has the email API in NetOS 7 changed significantly? Is there a chance it would fix the problem?

Can you look with a sniffer to the data traffic on ethernet? It may tell you at what level the function locks-up.


Done that. I have two customers who have the same problem. They’re both kinda tech-savy, so I got them to install Ethereal. For one, his NIC doesn’t support “promiscuous” mode, so he can’t see the ConnectME sending/receiving thru the gateway. The other customer - curiously enough we can see the ConnectME sending packets (DHCP and ARP for example), but never see the responses to them (though it looks like the ConnectME did receive a response). So, that’s pretty much useless for now.

I’m currently in touch with Digi Tech Suppt on this. I’ll post here if/when we find a resolution.

In the meantime, I’m still open to additional suggestions…

Do you have any
in the body of the messages? There are server which do not support that, it has to be replaced with

By “server,” do you mean SMTP server?

In this case, when we replace the ActionTec router with a D-Link or Linksys, it works fine. So no, it’s not anything odd with the SMTP server.

However, what you said could explain some other (unrelated) problems I’ve seen in the past. I’ll have to go back & check that later.

Some new info … it appears MCSendMail may not be locking up after all, but merely waiting a looooong time before returning. Without a good Ethereal trace, however, it’s difficult to diagnose.

I wish I gould get my hands on one of these routers.

It is hard to find without looking at a trace to see what’s going on. Look also at the error returned by the MCSendMail function, if any.

I’ve just seen that there is a new patch for 6.3 related to mail server connection problems, dated June,08,2007.
The description is “Server intermittently rejects connection attempt when using Digest-MD5 authentication”.
Have you tried this patch?