Maintain and Overwrite Customization during Importing

• Maintain customizations (recommended): Selecting this option will maintain any unmanaged customizations performed on components but also implies that some of the updates included in this solution will not take effect.
• Overwrite Customizations: Selecting this option overwrites any unmanaged customizations previously performed on components included in this solution. All updates included in this solution will take effect.

CRM 2011 Importing Data Limit/ Maximum Importing Data

Data Import Wizard Will not upload files past 32mb

Let say if your file is around 200mb in size. The web.config file has the maximum file size in it, so you can edit it to allow for bigger sizes or break the file up into smaller chunks.

Recommended
I prefer to temporarily raise the limits. Note. the data you are importing will takes times.

Default file Location
C:\Program Files\Microsoft Dynamics CRM Data Migration Manager\DMClient\res\web

file web.config

Default data in the file

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<system.web>
<httpRuntime executionTimeout="1200" maxRequestLength="32768"/>
<compilation defaultLanguage="C#" debug="false">
<assemblies>
<add assembly="Microsoft.Crm, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
<add assembly="Microsoft.Crm.Sdk, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
<add assembly="Microsoft.Crm.SdkTypeProxy, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
<add assembly="Microsoft.Crm.Platform.Sdk, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
</assemblies>
</compilation>
<authentication mode="Windows" />
<identity impersonate="true" />

</system.web>
</configuration>


I choose to modify maxRequestLength="32768" to be maxRequestLength="300000"

CRM 2011 Microsoft CRM Email Router Service Not Running

Step 1 - Run Services.msc
Step 2 - Locate Microsoft CRM Email Router
Step 3 - Start the services

Pro Rate Calculation (Rental And Service Cost)

Problem : How does pro rate work for rental.
*Note : Its different from all company.
There are 6 Condition will hit when u do pro rate calculation 

1. Rental Start <= Charge Start, Rental Start < Rental End < Charge End.
2. Rental End> Rental Start < Charge End., Rental End >= Charge End.
3. Rental Start <= Charge Start, Rental End >= Charge End.
4. Rental Start > Charge Start, Rental End < Charge End.
5. Rental Start < Charge Start, Rental End = Charge End.
6. Rental Start = Rental End.

Int32 DropdownMonth = 8;
Int32 DropdownYear = 2013;
int32 DaysActualPerMonth = 0;
int32 DaysPerMonth = 0;

// Eg. August bill September Rental
Int32 DaysInMonth = DateTime.DaysInMonth(DropdownYear, DropdownMonth + 1);
DateTime FirstDayOfTheMonth = GetFirstDayOfMonth(DropdownYear, DropdownMonth + 1);
DateTime LastDayOfTheMonth = GetLastDayOfMonth(DropdownYear, DropdownMonth + 1);

DateTime RentalCommenceDate = RentalCostCommenceDate; //Get Rental Commence Date
DateTime RentalDueDate = RentalCostDueDate; // Get Rental Due Date

//ParameterSetDateTime;  Equal to previous generation date. May bill invoice date = Invoice date (June Date)
if (RentalCommenceDate <= FirstDayOfTheMonth && RentalDueDate > RentalCommenceDate && RentalDueDate < LastDayOfTheMonth)
{
    //Return Partial Rental Amount (A)
    DaysActualPerMonth = DaysInMonth;
    DaysPerMonth = GetDaysBetweenDates(FirstDayOfTheMonth, RentalDueDate) + 1;
}
else if (RentalCommenceDate > FirstDayOfTheMonth && RentalCommenceDate < LastDayOfTheMonth && RentalDueDate >= LastDayOfTheMonth)
{
    //Return Partial Rental Amount (B)
    DaysActualPerMonth = DaysInMonth;
    DaysPerMonth = GetDaysBetweenDates(RentalCommenceDate, LastDayOfTheMonth) + 1;
}
else if (RentalCommenceDate <= FirstDayOfTheMonth && RentalDueDate >= LastDayOfTheMonth)
{
    //Return Full Rental Amount (C)
    DaysActualPerMonth = DaysInMonth;
    DaysPerMonth = DaysInMonth;
}
else if (RentalCommenceDate > FirstDayOfTheMonth && RentalDueDate > RentalCommenceDate && RentalDueDate < LastDayOfTheMonth)
{
    //Return Partial Rental Amount (D)
    DaysActualPerMonth = DaysInMonth;
    DaysPerMonth = GetDaysBetweenDates(RentalCommenceDate, RentalDueDate) + 1;
}
else if (RentalCommenceDate < FirstDayOfTheMonth && RentalDueDate > RentalCommenceDate && RentalDueDate == LastDayOfTheMonth)
{
    //Return Partial Rental Amount (E)
    DaysActualPerMonth = DaysInMonth;
    DaysPerMonth = 1;
}
else if (RentalCommenceDate == RentalDueDate)
{
    //Return Partial Rental Amount = One Day Rental (F)
    DaysActualPerMonth = DaysInMonth;
    DaysPerMonth = 1;
}
else
{
    //Nothing
}