Your email accounts are the engines of your campaign, and they need regular maintenance to perform well.
Poor account health—high bounce rates, spam complaints, or low engagement—can cripple your campaign.
You should check the health of your email accounts in at least every 2 weeks.
If you are seeing less than 1 percent reply rate when every other things in cold email is well-groomed, That means that your email accounts got damage and you need to change them with new ones.
Use tools like
mailreach or
emailguards to monitor your domain reputation, and implement warm-up tools to keep your accounts active.