I've been very satisfied with wp-mail-smtp, but required a customization to optionally send all e-mails by BCC: to a given address. This is very useful troubleshooting or occasionally re-sending messages that get stuck in spam filters.
If there is interest in incorporating such a feature in the plugin, I'd be happy to provide a patch (either on GH if there is a repository there or by attaching the patch to this threat)