Outgoing spam filtering rejecting lots of emails we're sending

We’ve started using the Comodo Outgoing email on a domain recently and many emails are not going out. When I search the outgoing log in Comodo it shows those emails classified as “Rejected”. When I download the log file I can see the message “,reject,generic-spam,” in those entries.

The SPF record for the domain has the originating server’s IP correctly defined, and “include:_spf.spamgateway.comodo.com”. MX Toolbox shows the SPF is setup correctly and MX records are correct (although we don’t have DKIM setup yet).

The emails we’re trying to send contain formatted HTML, and also contain an embedded link to a webpage with a .aspx ending.

Anyone have any suggestions on what might be going wrong here or what else we can try?

Thanks.

I had this from to one particular domain and it was that we were forwarding to that domain. The SPF and MX records are not used at this point as SPF is for the receiving domain and the MX records are for sending to you.

Have you correctly setup the outgoing users per user or by IP address?
Are the errors coming from one user or all users?

I do not work for Comodo and only trying to offer help.

Thanks, appreciate your comments.

Not sure what you mean by setting up the outgoing users per user or by IP address? We only have one Outgoing user configured in Comodo that our SMTP servers Smarthost uses to authenticate to Comodo for sending. It isn’t possible to use more than one that purpose with SmartHost.

Do you mean I need to setup a user such as 114.234.543.123@mydomain.com so all incoming emails from our SMTP server at 114.234.543.123 are accepted?

No that setting is fine if all emails are being routed from that IP address.

What happens if you send one of the rejected email to another domain, does it get through?