We currently limit attachments to 20MB in size due to many email providers blocking anything larger than that.
We will also not attach a file with any of the following file types as email providers (Google) may also block emails that include these attachments:
.ade, .adp, .apk, .appx, .appxbundle, .bat, .cab, .chm, .cmd, .com, .cpl, .dll, .dmg, .ex, .ex_, .exe, .hta, .ins, .isp, .iso, .jar, .js, .jse, .lib, .lnk, .mde, .msc, .msi, .msix, .msixbundle, .msp, .mst, .nsh, .pif, .ps1, .scr, .sct, .shb, .sys, .vb, .vbe, .vbs, .vxd, .wsc, .wsf, .wsh