POP.Host := 'bla-bla'
POP.Port := 'bla-bla'
POP.UserID := 'bla-bla'
POP.Password := 'bla-bla'
POP.Connect;
if POP.CheckMessages> 0  then //количество писем
begin
Msg.Clear;
POP.Retrieve( 1 , Msg); // 1 -номер письма
if msg.Subject='721381723_give_me_price' then
begin
for c :=  0  to Msg.MessageParts.Count -  1  do
begin
if Msg.MessageParts.Items[c] is TIdAttachment then
begin
if fileexists(TIdAttachment(Msg.MessageParts.Items[c]).FileName) then
deletefile(TIdAttachment(Msg.MessageParts.Items[c]).FileName);
TIdAttachment(Msg.MessageParts.Items[c]).SaveToFile(TIdAttachment(Msg.MessageParts.Items[c]).FileName);
end
else
if Msg.MessageParts.Items[c] is TIdText then
begin
 Memo1.Lines.Clear;
 Memo1.Lines.AddStrings(TIdText(Msg.MessageParts.Items[c]).Body);
end;
end;
POP.Delete( 1 );//удаление письма (первого)
end;
end;
if pop.Connected then POP.Disconnect;