Contact form not submitting for certain email domains

[primogenie]

My site is live at www.marcmcgovern.com

I've used Muse's built-in contact form for the form at the bottom of the page under the "get involved" section. The form gets successfully submitted and the email received when I use certain domains like @BU.edu, or @inmotionhosting.com, but when I use an address with @gmail.com or @yahoo.com, I get the error message I've coded in: The server encountered an error. Please check your internet connection or refresh the page

I've talked to my host's support and they weren't able to find any issues on their end. Any ideas? The recipient address is @gmail

[Ussnorway]

sorry I got bored waiting for the site to load... will try again after work mate

[primogenie]

Was it truly that slow to load? Almost instant for me.. :*(

[Ussnorway]

your device has it stored then... yes its VERY slow