Send email through Outlook with a DeferredDeliveryTime

Dear all,

I have designed a script to send automated emails to all my experiment participants (i.e. 48 hours before each experimental session):

% Importing the excel file containing participants information
ExcelPath = [pwd '\MailDataBase.xlsx'];
DataTable = readtable(ExcelPath);
DataCells = table2cell(DataTable);

% Parameters
UserName=getenv('USERNAME');

% Will only send email to participants that have not yet been contacted
% (last column of excel file should be 1 = already sent, 0 = not sent yet
for k=1:size(DataCells,1)
    if DataCells{k,end} ~= 1
        
        % Store data to be sent
        MailList(k) = DataCells(k,1);
        MailSubj(k) = {sprintf('! Caffeine experiment reminder for session %d (in 48h) !',DataCells{k,end-1})};
        MailDates(k) = {datenum(DataCells{k,3})};
        ExpDates(k) = DataCells(k,2);
        
        % Update the last column (1 = mail is sent)
        DataCells(k,end) = {1};
    end
end

% For each mail to be sent
for k=1:length(MailList)
    
    % Clear data
    if exist('mail','var'); clear mail; end
    if exist('h','var'); clear h; end
    
    % Initialize connection with Outlook
    h = actxserver('outlook.Application');
    
    % Load signature (if any)
    SigFiles = dir(['C:\Users\' UserName '\AppData\Roaming\Microsoft\Signatures\' '*.htm']);
    if ~isempty(SigFiles) % Problem if more than 1 signature !! 
        SigFile = [SigFiles(1).folder '\' SigFiles(1).name]; 
    end
    Signature = getSig(h,SigFile);
    
    % Initialize local parameters
    bodyHTML1 = getSig(h,[pwd '\MailContent1.html']);
    bodyHTML2 = getSig(h,[pwd '\MailContent2.html']); 
    bodyHTML = [bodyHTML1 sprintf('%s',ExpDates{k}) bodyHTML2];

    %Sends email using MS Outlook. The format of the function is 
    %Similar to the SENDMAIL command.
    % Taken from:
    % https://ch.mathworks.com/matlabcentral/answers/94446-can-i-send-e-mail-through-matlab-using-microsoft-outlook

    % Create object and set parameters.
    mail = h.CreateItem('olMail');
    mail.Subject = MailSubj{k};
    mail.To = MailList{k};
    mail.Cc = '[e-mail]'; % Might be useless since stored in emails sent ! 
    mail.BodyFormat = 'olFormatHTML';
    mail.HTMLBody = [bodyHTML '<br><br>' Signature];
    mail.DeferredDeliveryTime = [datestr(MailDates{k},'dd/mm/yyyy') ' ' '10:15:00 AM']; % NOT WORKING !!! SHIT 
    
    % Send message and release object
    mail.Send;
    h.release;
end

% Update the excel file
DataTableOut = cell2table(DataCells); 
DataTableOut.Properties.VariableNames = DataTable.Properties.VariableNames;
writetable(DataTableOut,ExcelPath);
fprintf('The excel table has been updated in: %s\n',ExcelPath);

% Modified GetBoiler function from Ron de Bruin's Excel Automation post
function sig = getSig(h, sFile)
    fso = h.CreateObject('Scripting.FileSystemObject');
    ts = fso.GetFile(sFile).OpenAsTextStream(1, -2);
    sig = ts.ReadAll;
    ts.Close;
end

Most of the code is inspired from:

https://ch.mathworks.com/matlabcentral/answers/94446-can-i-send-e-mail-through-matlab-using-microsoft-outlook

Regarding the possibility to differ the delivery time/date, I found a line of code here:

https://kr.mathworks.com/matlabcentral/mlc-downloads/downloads/submissions/43249/versions/3/previews/sendOutlookMailv2.m/index.html

My problem is that mail.DeferredDeliveryTime seems to store something (code works fine) but the mail(s) get(s) sent immediately, hence the delay is not working..

Would you have any explanation?

Best regards,

Corentin Wicht