To be absolutely brutal and honest with you, nobody cares about I look forward to hearing from you.. The practical reason is that it's one of the various standard and conventionally polite ways to end the body of the letter. It's just a standard exit.
1 In some cases, liver failure causes this taste to occur. 2  Gastroesophogal reflux disease can cause the salty taste (even when no pain is present). 3  Some medicines can make everything taste odd. for example the drug enalapril, which is a drug used to prevent heart failure.
It is also important to differentiate if the taste is truly salty, or if it is more metallic in nature. A metallic taste is usually caused by bleeding in the mouth or as a side effect of a medication. A salty taste on the lips, and in the mouth can have a wide range of causes, some very common, some very rare.