To calculate the right sample size, you need to consider several factors:
Confidence Level: Typically set at 95%, this indicates how sure you can be that your results are accurate. Margin of Error: This is the range within which the true value lies, often set at 5%. Population Size: This is the total number of people in your email list. Standard Deviation: A measure of variation in your data, usually assumed to be 0.5 for unknown populations.