Many companies have the occasional “oops” where they send email they probably shouldn’t have. This can often cause a decrease in reputation and subsequent delivery problems. Some companies rush to fix things by changing domains.
Getting a new domain does not fix the problem!
Brand new domains, those registered less than 30 days, have really bad reputations. Blame the spammers and scammers who exploited a loophole and sent tons of untraceable spam from newly registered domains that they then abandoned without paying for them. So unless you have a domain waiting in the wings you’re not going to improve your reputation by switching.
Even if you do have a registered but unused domain in your back pocket, moving to that domain isn’t going to help. These days, domains need to be warmed just like IPs do. Depending on where you’re mailing, warmup can take 4 – 6 weeks to accomplish. Domains need to be warmed even if you’re putting them on currently warmed IPs.
Fundamentally, it’s easier to rebuild a domain reputation than it is to warm up a new domain. This is especially true when the reputation destroying incident is a one-time or short term thing. For instance, sometimes a company will need to send a legal notice to their whole database. This may hurt overall domain reputation in the short term. However, if there’s a history of good mail and the sends quickly return to that good place, then reputation won’t be damaged over the long term.
Companies that panic and switch domains are stuck warming up for weeks. They don’t have the history behind them that compensates for short term problems.
Even in the cases where there have been ongoing and long term problems, filters will often adapt faster to good practices on an established domain than they will to good practices on a new domain.
Changing domains is (almost) never the solutions to domain reputation problems.