Golang Experience

I am using golang git [login to view URL] there is some errors are coming while i connect to mozilla thunderbird 2017/09/26 23:51:14 Starting IMAP server at localhost:1143 <f3a35ec8f854b84599c2fd970de3985533bec28bc5b2a68e> <f3a35ec8f854b84599c2fd970de3985533bec28bc5b2a68e> panic: assignment to entry in nil map goroutine 26 [running]: panic(0x8253e0, 0xc82026ffe0) /usr/lib/go-1.6/src/runtime/[login to view URL] +0x3e6 [login to view URL](0x7f5f2dcdadc8, 0xc820295340, 0xc820283ad0, 0x9331c0) /home/ubuntu/work/src/[login to view URL]:54 +0x308 [login to view URL](0x7f5f2dcdadc8, 0xc820295340, 0xc820283ad0, 0x40d2d8, 0x0, 0x0) /home/ubuntu/work/src/[login to view URL]:71 +0x45 [login to view URL](0xc820283bf0, 0xc8201e9d40, 0x0, 0x0, 0x0, 0x0) /home/ubuntu/work/src/[login to view URL]:44 +0x3c1 [login to view URL](*Message).Fetch(0xc82005b800, 0x3, 0xc8201e9840, 0x4, 0x4, 0xc820275200, 0x0, 0x0) /home/ubuntu/work/src/[login to view URL]:49 +0x3f6 [login to view URL](*Mailbox).ListMessages(0xc8201e9340, 0xa85901, 0xc820296a20, 0xc8201e9840, 0x4, 0x4, 0xc8202a2540, 0x0, 0x0) /home/ubuntu/work/src/[login to view URL]:110 +0x184 [login to view URL](*Fetch).handle(0xc820296a00, 0x1, 0x7f5f2dc95268, 0xc820187b30, 0x0, 0x0) /home/ubuntu/work/src/[login to view URL]:168 +0x1c0 [login to view URL](*Fetch).UidHandle(0xc820296a00, 0x7f5f2dc95268, 0xc820187b30, 0x0, 0x0) /home/ubuntu/work/src/[login to view URL]:193 +0x175 [login to view URL](*Uid).Handle(0xc82026e9c0, 0x7f5f2dc95268, 0xc820187b30, 0x0, 0x0) /home/ubuntu/work/src/[login to view URL]:305 +0x248 [login to view URL](*conn).handleCommand(0xc820187b30, 0xc820245ec8, 0x0, 0x0, 0x0, 0x0, 0x0) /home/ubuntu/work/src/[login to view URL]:366 +0x1b8 [login to view URL](*conn).serve(0xc820187b30, 0x0, 0x0) /home/ubuntu/work/src/[login to view URL]:313 +0xca2 [login to view URL](*Server).serveConn(0xc820190000, 0x7f5f2dc95268, 0xc820187b30, 0x0, 0x0) /home/ubuntu/work/src/[login to view URL]:279 +0xec created by [login to view URL](*Server).Serve /home/ubuntu/work/src/[login to view URL]:227 +0x35a my budget is $50