Every recipient server is different and may apply different spam filtering criteria for the messages being received. In most cases, recipient servers don't provide any information about spam filtering to the sender of an email that was filtered. It would give too much information to spammers who would use that data to get around spam filters.

Spam filters are constantly changing to adapt to new techniques and types of spam messages, so what lands in the inbox today could be spam filtered tomorrow. There are some things you can do to help ensure your emails are being delivered to the inbox.

Use the Outbound Email Control tool to experiment with a solution or a combination of solutions.  There is no one shot fix...  after all, the message is buried in a spam folder and is not visible.  Therefore, there will be no descriptions regarding what triggered the spam filter.  

Experiment with the tools on this screen or talk with your receiving IT Department - see if you can get more of an explanation of why they weren't delivered.

rsvpBOOK has 2 versions of the Admin Dashboard.  Which one do you have?

The 3 checkboxes are your primary tools for troubleshooting and possibly defeating spam filtering.  None of these are certain because all ISPs have their own rules for what is considered spam.  Additionally, what is considered spam constantly changes because of new developments in technology.

This screenshot has all 3 checkboxes turned on.

1. Sent from: via rsvpBOOK - this is the easiest (one click checkbox) to set up
2. Use your company's email server for sending rsvpBOOK email messages
3. Send from: [email protected] - this option is the least effective in terms of getting your email message through the spam filters

Recommended use of this screen:

Turn on checkbox #1 and wait a day or two to see if any reduction in spam bouncebacks occur.  If the number of spam bouncebacks diminishes, then this was a good choice.

Turn on checkbox #2 if you are still seeing bouncebacks due to spam filtering.  It is likely that this option will eliminate the problem entirely because mail is coming FROM your company's domain. Therefore, there is no conflict between the sender's domain and the mail server's domain.  

Checkbox #3 is the least effective overall for avoiding spam filters.  In fact, this option is a widely known method that spammers use to send email using someone else's mail account. This is not recommended if you have heavy spam bouncebacks.

So start with checkbox #1 and then add checkbox #2 if necessary.  If you're using checkbox #1 or #2, checkbox #3 should not be used.

1. The sending server is on a Black List - See this help document: What do I do if I'm on a Black List?
2. The SPF Record attached to the sending domain (example: YourCompanyDomain.com) blocks rsvpBOOK.com from sending email that "claims" to be from YourCompanyDomain.com - See this help document: What do I do if I have an SPF issue?
3. The email address was incorrectly entered by the registrant (a typo) - See this help document: What do I do if the registrant submits an erroneous email address?
4. 100 Spam Trigger Words & Phrases To Avoid