How serious are MXToolBox blacklistings and what should I do about rented email lists?

Email marketer from Constant Contact explains regularly cleaning up your lists, you will see increased deliverability, reduce spam complaints, protect your sender reputation, and improve overall marketing results. Cleaning your list ensures that you're sending messages only to interested and engaged contacts, which helps search engines and inbox providers trust you with their users.

Email marketer from Reddit explains that renting email lists is a bad idea because the recipients haven't opted in to receive emails from you. This will likely result in low engagement, high bounce rates, spam complaints, and damage to your sender reputation.

Email marketer from Reddit explains that when dealing with blacklists, find out why you were added, what their removal process is, fix the problem, follow the blacklist removal process and monitor your reputation afterwards.

Email marketer from WebHostingTalk Forum says that smaller blacklists may have little or no impact, but being listed on a larger blacklist means email can be rejected by servers running the larger blacklist

Email marketer from Litmus explains you should not buy lists, they are ineffective as your emails will be considered as spam and it can violate GDPR and other privacy laws and damage reputation.

Email marketer from Email on Acid highlights the importance of monitoring your sender reputation and IP address to detect blacklist listings early. They recommend using tools to track your reputation and identify any potential issues.

Marketer from Email Geeks shares a success story of a financial services client who transitioned from spamming to good sending practices, resulting in better revenue.

Email marketer from SendPulse advises users to avoid blacklists by obtaining explicit consent, using double opt-in, regularly cleaning their lists, and authenticating their email.

Email marketer from Mailjet warns that using rented or purchased email lists is a violation of their Terms of Service, can harm your sender reputation, and result in account suspension. They strongly advise against this practice.

Email marketer from GMass says you will be blacklisted for Reasons like Spam Complaints, Sending unsolicited email, Poor email list hygiene, sending malicious content, Sending from a compromised server or computer and having Poor authentication (SPF, DKIM, DMARC).

Expert from Email Geeks states that using rented lists is spamming and will lead to being blocked. Skyler (SocketLabs) agrees, stating it is unsolicited email and therefore spam.

Expert from Word to the Wise explains that purchased/rented lists violate ESP policies, introduce spam traps, result in low engagement, and are not a sustainable marketing strategy.

Expert from Email Geeks explains that the blacklistings are unlikely to be a serious problem, but if you're doing something bad to get listed, that bad thing could get you blocked elsewhere.

Expert from Spamresource explains that you have to be proactive and identify any problems with a list by checking for invalid email addresses, spam traps and unengaged subscribers.

Expert from Word to the Wise explains that evaluating the impact of a blacklist involves looking at where you're sending email, the type of blacklist (reputation or content), and whether the listing is causing delivery problems. She says some lists matter more than others.

Expert from Email Geeks explains that bad mailbox bounces can be a sign your acquisition process has problems.

Documentation from Spamhaus explains that being listed on their Blocklist (SBL) indicates a serious issue with your email sending practices. They advise investigating the listing reason and taking corrective action to be removed from the list.

Documentation from SparkPost explains that regular list cleaning should involve removing Hard bounces, Unengaged subscribers, Spam complaints and Typographical errors

Documentation from Google states that maintaining a low spam rate (below 0.10%) is crucial for ensuring email deliverability to Gmail users. Exceeding this threshold can negatively impact inbox placement.

Documentation from MXToolbox explains that using their blacklist monitoring tools can help identify if your server or domain is listed on various DNS-based blacklists (DNSBLs) and provides guidance on how to investigate and request delisting.

Documentation from Microsoft explains that exceeding sending limits can lead to your IP address being blacklisted by their systems. They recommend adhering to their sending guidelines and monitoring your sender reputation.