If you know your emails are in recipient's Spam folders and if these recipients use Gmail addresses and have told you, which is how you know, you then ask them to select your emails from the Spam folder and then select the Report as not spam button. This will tell Gmail not to dump your mail messages into their Spam folder but to deliver your future messages into the Inbox where all fully authenticated mail should be delivered. TalkTalk Mail is sent with full authentication.
Which mail services are not accepting delivery of your emails and do you get any bounceback error message as a Delivery Notification Fail?
