For best performance, SOQL queries must be selective, particularly for queries inside of triggers. To avoid long execution times, non-selective SOQL queries may be terminated by the system. Developers will receive an error message when a non-selective query in a trigger executes against an object that contains more than 100,000 records. To avoid this error, ensure that the query is selective.
The maximum number of records that an event report returns for a user who is not a system administrator is 20000; for system administrators is 100000.
Inbound Email Services: Maximum Number of Email Messages Processed (Includes limit for On-Demand Email-to-Case) is number of user licenses multiplied by 1000, up to a daily maximum of 1,000,000.
Inbound Email Services: Maximum Size of Email Message (Body and Attachments) is 10 MB.
Apex Limit: Maximum number of characters for a class is 1 million.
Apex Limit: Maximum number of characters for a trigger is 1 million.
Apex Limit: Maximum amount of code used by all Apex code in an organization1 is 3 MB.
Apex Limit: Default timeout of callouts (HTTP requests or Web services calls) in a transaction is 10 seconds.
Apex Limit: Maximum size of callout request or response (HTTP request or Web services call) is 3 MB.
Apex Limit: Maximum SOQL query run time before the transaction can be canceled by Salesforce is 120 seconds.
Apex Limit: Maximum number of class and trigger code units in a deployment of Apex is 5,000.