[CalvinC]

Read the error message. "Default:" needs to be in a switch.
Example:

pawn Код:

switch(Something)
    {
        case 1:
        {
            // Do something
        }
        case 2:
        {
            // Do something
        }
        default:
        {
            // Do something
        }

Not entirely sure about logstring, you could maybe try moving this

pawn Код:

new logstring[128];

down just above the logstring error.
The last warning, again im not sure, but you can try removing

pawn Код:

query[128]

Like this

pawn Код:

new field[256], DBResult:result;
    result = db_query(MailDB, "SELECT * FROM `Letters`"); // line 124464
    if (db_num_rows(result) != 0)
    {