Resemble: have qualities or features, especially those of appearance, in common with (someone or something); look or seem like: some people resemble their dogs | they seemed to resemble each other closely.
Resent: feel bitterness or indignation at (a circumstance, action, or person): she resented the fact that I had children.
I think the second one fits better, you resent that the parent poster called MailChimp "spam"
I use MailChimp to keep in touch with customers. They love it.