Sorry about that.
Symantec is willing, purely as a discretionary matter, to investigate the reason why your company's messages may be blocked by our filtering software. Please contact investigation@review.symantec.com and submit an example of a message that's getting blocked, sent in the exact same way you would send to your customers.
The investigation uses the provided sample(s) for analysis to determine why the message is being blocked. It's important the sample be sent in the exact same way you send messages to your customers. Please allow 7 business days for the completion of the investigation. Once the investigation is complete a Symantec representative will contact you through email with the results of our investigation.
To make sure your email addresses are legitimate, Symantec recommends the following:
- Make sure your database does not contain older email addresses of those who do not want to receive your promotional or marketing email. Send confirmation emails to determine who should remain on your list and who to remove.
- Do not accept email addresses from third party marketers, unless you can assure that such email addresses are legitimate and that such subscribers want to receive your promotional or marketing email.
- If a subscriber no longer wants to receive your emails, provide a method by which a subscriber can opt-out. Promptly remove these opted-out email addresses from your list.
- Promptly remove from your email list emails that bounce back to you. This indicates that the recipient is no longer available.
- Use a double opt-in method to sign up subscribers. This will confirm that the subscriber did request your promotional and marketing email.
- Remove email addresses of those who do not open your email messages.
- Consider using a third party to manage and update the addresses on your email list.
The above bullets are some of the reasons why email is being tagged spam. Old unverified third party email lists result in subscribers feeling they receive unsolicited email. Implementing these suggestions are a best practice recommendation by Symantec.
For your information, I didn't find another blacklist that listed your email domain.