Some investors rely on dividends for growing their wealth, and if you're one of those dividend sleuths, you might be intrigued to know that Trustmark Corporation (NASDAQ:TRMK) is about to go ex-dividend in just four days. The ex-dividend date occurs one day before the record date which is the day on which shareholders need to be on the company's books in order to receive a dividend. It is important to be aware of the ex-dividend date because any trade on the stock needs to have been settled on or before the record date. Meaning, you will need to purchase Trustmark's shares before the 28th of February to receive the dividend, which will be paid on the 15th of March.

The company's upcoming dividend is US$0.24 a share, following on from the last 12 months, when the company distributed a total of US$0.96 per share to shareholders. Looking at the last 12 months of distributions, Trustmark has a trailing yield of approximately 2.6% on its current stock price of US$36.50. Dividends are a major contributor to investment returns for long term holders, but only if the dividend continues to be paid. That's why we should always check whether the dividend payments appear sustainable, and if the company is growing.

View our latest analysis for Trustmark

Dividends are typically paid out of company income, so if a company pays out more than it earned, its dividend is usually at a higher risk of being cut. Trustmark distributed an unsustainably high 124% of its profit as dividends to shareholders last year. Without extenuating circumstances, we'd consider the dividend at risk of a cut.

When the dividend payout ratio is high, as it is in this case, the dividend is usually at greater risk of being cut in the future.

Click here to see the company's payout ratio, plus analyst estimates of its future dividends.

Have Earnings And Dividends Been Growing?

Companies with falling earnings are riskier for dividend shareholders. If earnings fall far enough, the company could be forced to cut its dividend. Trustmark's earnings per share have fallen at approximately 20% a year over the previous five years. Such a sharp decline casts doubt on the future sustainability of the dividend.

The main way most investors will assess a company's dividend prospects is by checking the historical rate of dividend growth. It looks like the Trustmark dividends are largely the same as they were 10 years ago. If a company's dividend stays flat while earnings are in decline, this is typically a sign that it is paying out a larger percentage of its earnings. This can become unsustainable if earnings fall far enough.