Google Apps does in fact have limits: https://support.google.com/a/answer/166852?hl=en

If you need to do more than that, use MailChimp or the like.

One of the many reasons I use ChilKat for all kinds of connectivity (email, ftp, sftp, ftps, http) is the detail error messages that pinpoint the exact cause of the connectivity error.

hth,

Hank

>>>Any ideas?
>>
>>A guess, but might it be limitations set by the SMTP server or ISP? Some have limitations such as:
>>
>>- Total # of messages per hour and per day
>>- Total # of recipients per hour and per day
>>- Total size of messages per hour and per day
>>
>>If you hit such a limitation you typically don't get any sort of error message or warning. I don't know how an SMTP server or ISP might respond to a perceived violation, but it's not impossible whatever they do could hang a SEND().
>>
>>If you have a good relationship with the server owner or ISP you could ask them if they've logged any unusual events around the times you're seeing these intermittent errors.
>
>
>Thanks Al. We're actually sending to smtp.gmail.com as we use Google Apps for Business.
>
>There should never be a circumstance that .send() completely hangs. What's the point of a timeout if there are scenarios that never time out?
>
>If I can't resolve this issue I'll be forced to dump CDO and use a commercial alternative.
>
>When the black box behaves, it's awesome. When the blackbox misbehaves, you're screwed.