how to convert an array into string?

Question

How can I convert array into string if I will use it for NSDictionary? And the dictionary will be used as params in JSON.

This is my code.

'_emailsInApi = [[DBManager getSharedInstance]arrayOfEmails];

NSDictionary *params =@{@"api_key":@"APIKEY",@"action":@"get-status",@"email":[[[DBManager getInstance]Emails]description]};'

and this is the NSLog

array: (
    "<Inquiry: 0x10d14cce0>",
    "<Inquiry: 0x1092db900>",
    "<Inquiry: 0x1092db9b0>",
    "<Inquiry: 0x10d148610>",
    "<Inquiry: 0x10d148690>",
    "<Inquiry: 0x10d148710>",
    "<Inquiry: 0x10d176fb0>",
    "<Inquiry: 0x10d1770a0>",
    "<Inquiry: 0x10d1d6610>",
    "<Inquiry: 0x10d1d66c0>",
    "<Inquiry: 0x1092d93f0>",
    "<Inquiry: 0x1092d32c0>",
    "<Inquiry: 0x1092d3340>",
    "<Inquiry: 0x1092d33c0>",
    "<Inquiry: 0x10d1482a0>"
)

This is causing the API to return that some emails are invalid.

My question is: how can I convert _emailsInApi(the array) into a string. So that it's values will be like myemail@email.com, secondemail@email.com .....

Thanks for any help.