Use the right kind of link
Ensure you have the DNS in the survey link rather than the IP address, e.g. use:
http://www.server.com/WebProd/cgi-bin/askiaext.dll?Action=StartSurvey&SurveyName=_SAmulti4 instead of http://192.168.0.1/WebProd/cgi-bin/askiaext.dll?Action=StartSurvey&SurveyName=_SAmulti4
Batch frequency of emails
For this point, the defaults for each new list uploaded can be found in the below menus. You can change these per list also by going to list properties > Mailing > Mail grouping: Override defaults.
Images / animations in email
The fewer there are and the closer your email is to plain text the better for avoiding the varying strengths of spam filters. If you have to include an image: insert a link to the image: (example, http://www.server.com/WebProd/Resources/logo.jpg ) rather than an attachment.
Make sure to use the same domain as your invitation link and avoid using resources that aren't hosted on the same domain.
On the same theme, a small, ‘hidden’ image is added by CCA to invites to record when an email is opened (email detection link). This is counted in List > Monitor > Statistics on mails > Not yet read / read figures. This image is added when you have an open and close body tag in the email invite.
Even the content of the email can determine whether or not your email campaign will end up in spam filters. Make sure to avoid using "How to make money by answering an online survey" or any sentence that could be mistaken with a scam. Remember that if many people mark you email as spam, il will increase the likelihood of mail providers to automatically flag your emails as spam in later campaigns.
You or your IT department must check the following:
Sender Policy Framework (SPF)
This is used to identify 'spoofed' emails. If emails are being rejected, check the domain name for an SPF record. E.g. your company's servers may not be on any blacklists but if the reply address (Reply-To, FROM) has a domain name that is not yourcompany.com then it is important to make sure the SPF file includes your servers (smtp.xxx.xxx.com, 01.01.010.1/01) as authorised senders.
This is an example of an emailing flagged as junk-mail because senders were not on the authorised servers list:
Received-SPF: softfail (google.com: domain of transitioning mailto:firstname.lastname@example.org does not designate 01.01.010.1 as permitted sender) client-ip=01.01.010.1;
You can check your DNS entry here: http://www.kitterman.com/spf/validate.html
Or here : https://mxtoolbox.com . This is an example of a good SPF record for the yourcompany.com domain:
v=spf1 a ip4: 01.01.010.1/01 ip4:010.101.010.1/01 include:_spf.google.com include:_spf.zdsys.com ~all
You can also check the mail-server logs - some servers will reject a message immediately, while others will allow them but fail them internally.
Finally, remember to . . .
Test before you send
There are a few email testers out there, and something like https://www.mail-tester.com gives a pretty accurate estimation of the likelihood of your email being flagged as spam.
Use the "send test email" feature in Supervisor, and send your test to the email address provided by https://www.mail-tester.com to get the results.