The sentence goes as follows:
The sentence is uttered after the reader is told about a woman who works in a call center. She is checking the daily "briefing-mails" and then it is uttered.
The preceding sentence:
It is later revealed that there have been problems with telephones services all over town.
I really do not know what to make of the part in bold. My best shot at it would be that it expresses the fact that the company (the call center belongs to) is affiliated with all sorts of things (and therefore with the telephone problems as well). However, the meaning of 「傘下」is a mystery to me.