Why are outgoing emails delivered to the SPAM folder?
Outgoing Email, Spam
Emails sent to Gmail addresses are being placed in the Spam folder
The first step in the investigation would be to confirm if this happens in other email providers such as Yahoo and Microsoft. After confirming that this is happening only in Gmail, the next step is to analyze the email header to see if it passes the SPF, DKIM, and DMARC checks. If these checks are passed, then this would be a reputation issue, and these could be the various reasons for reputation damage:
- Shared IP range – the reputation could not be managed properly as the range of IPs being used by other senders as well.
- Spam complaints – Higher number of people marking your emails spam.
- Inconsistent volume sent from the instance.
- Used spammy words/sentence in the template.
- Establish a solid foundation by using a dedicated IP address (one each for promotional and transactional messaging).
- Keep your identity consistent – don’t change IP addresses and use the same domain or sub-domain for all your mailings.
- Authentication is a must-have. Utilize all the technologies available – SPF, DKIM, Dmarc – to cover your bases.
Gmail recommends confirmed opt-in (double opt-in) – Allow your users to check the opt-in box themselves and then send a confirmation notice before proceeding with promotional messaging.
- Gmail’s anti-spam filter is one of the best in the field. Google continues to improve and evolve the filter each day based on user feedback.
- Spam complaints are the single most damaging factor to a sender’s reputation at Gmail. But positive actions can improve Inbox placement such as – starred messages, messages moved from Spam to Inbox folder, opens and clicks.
- Poor authentication is a non-starter at Gmail. Messages that can’t be authenticated will trigger a “question mark” icon in the Gmail UI and will land in the Spam folder.
- Google is a huge proponent of encrypted communications (TLS). In 2016, Gmail began identifying senders who use unencrypted mail server connections by displaying a “broken lock” red icon in the Gmail UI. This by itself will not hurt deliverability but has obvious implications for the perceived trustworthiness of your brand.
In their sender guidelines, Gmail states “Gmail users can mark and unmark any message as spam, at any time. To increase the inbox delivery rate of your messages, make sure that all recipients on your distribution lists actually want to receive the mail”. For additional insight, review Gmail's Bulk Sender Guidelines.
When deliverability goes wrong at Gmail we recommend rethinking your audience segmentation. Mail only to engaged users – those with recent opens or clicks. Review our engagement based segmentation document for more information.
In addition, an ongoing process of removing disinterested recipients is the best course of action for preventing future deliverability problems. If they haven’t opened or clicked in a while, it’s time to stop mailing them.