~と(が)相まって => combining / together with… N1
Attached
に相違ない => without a doubt; certain; sure N2
を[境「さかい」]に => A is set as a border/limit N1
Degree/ Level/Amount
~ひょうしに(~拍子に)   => the moment [A], unintentionally / inadvertently caused something to happen N1
に[相違「そうい」]ない => No doubt N2
Information, Report
と[相「あい」]まって => Along with A N1
Lists, examples
と伝えていただけませんか => Could you tell, Could you convey N4
ように言う/頼む/注意する/伝える => to convey; to report; to transmit; to communicate; to tell; to impart; to propagate; to teach. N3