Dear colleagues,

I find myself once again facing the issue of emails being marked as spam.

This time, I have been unable to find a solution. I am curious about how you handle this situation and how you manage to remove your projects from spam lists, as well as how they end up there in the first place.

Here are the facts:

1. The mail servers that send the emails are not listed as spam.

2. The IP address used to send the emails matches the MX record of the mail server domain.

3. The outgoing address corresponds to the mail server's address.

4. The email address from which the message is sent actually exists.

5. The domain is newly registered and has not appeared on any spam lists or blacklists.

6. Only a maximum of 10 emails have been sent from this domain, all with different content.

7. Emails are immediately marked as spam by Google and Hotmail.

8. I have registered the project on Google and installed all the necessary codes.

Unfortunately, the emails still end up in spam. This is a significant problem because the entire purpose of the project is for people to generate personal calendars and share them with their friends.

I would greatly appreciate any information or assistance regarding this matter.

Thank you in advance.

Let's start by organizing things in the DNS:

1.

$ host 109.95.208.165
165.208.95.109.in-addr.arpa returns the domain name index www.colocat.com

$ host www.colocat.com
www.colocat.com is associated with the IP address 109.95.208.164

2.

$ host 94.228.168.67
67.168.228.94.in-addr.arpa returns the domain name index mail.colocat.com .

$ host mail.colocat.com
mail.colocat.com is associated with the IP address 109.95.208.165

Another option is to include a TXT record with the value "v=spf1 +a +mx -all".

It is important to check if your mailers' IP address has a PTR record. Ideally, it should exist and match the MX record.

Take a closer look at the headers of a spam email; some mailers include information about why it was marked as spam.

In general, consider using an external and trustworthy SMTP service to avoid unnecessary complications and frustrations.

It's important to understand how email spam filters work. They typically analyze the content of the email, the sender's reputation, and the email's technical characteristics. Even if your domain and IP address are not blacklisted, certain keywords, formatting, or other factors can trigger spam filters.

Based on the information you provided, here are some potential solutions and best practices:

1. Content and Formatting:
  - Avoid using excessive capitalization, excessive punctuation, or spammy-sounding subject lines.
  - Ensure your emails have a good balance of text and HTML, with relevant images and formatting.
  - Avoid using typical spam trigger words or phrases, such as "free," "make money," or "act now."

2. Email Authentication:
  - Implement email authentication protocols like SPF (Sender Policy Framework), DKIM (DomainKeys Identified Mail), and DMARC (Domain-based Message Authentication, Reporting & Conformance). These protocols help ISPs and spam filters verify the legitimacy of your emails.

3. Warm-up Process:
  - If you're sending emails from a brand-new domain or IP address, gradually increase the volume of emails over time. This "warm-up" process helps establish your reputation as a legitimate sender.

4. List Hygiene:
  - Ensure that your email lists are up-to-date and consist of active, engaged subscribers who have explicitly opted-in to receive your communications.
  - Remove inactive or invalid email addresses periodically to maintain a clean list.

5. Email Service Provider (ESP):
  - Consider using a reputable ESP that has established relationships with major ISPs and email providers. ESPs often have better deliverability rates and can provide guidance on best practices.

6. Feedback Loops:
  - Sign up for feedback loops with major email providers like Google and Microsoft. These loops provide feedback on emails that are marked as spam, allowing you to identify and address any issues.

7. Monitoring and Analysis:
  - Monitor your email delivery rates, open rates, and bounce rates. Analyze any patterns or trends that may indicate issues with deliverability.
  - Use email analysis tools to identify potential problems with your emails and make necessary adjustments.

8. Whitelisting and Feedback:
  - Encourage your subscribers to whitelist or add your email address to their address book to ensure your emails land in their inboxes.
  - Provide clear instructions for subscribers to report legitimate emails that end up in their spam folders, as this feedback can help improve your reputation with email providers.

Email deliverability is an ongoing process, and you may need to continuously monitor and adjust your strategies based on the latest trends and best practices. Additionally, maintaining a good sender reputation and respecting email marketing regulations can go a long way in ensuring your emails reach their intended recipients.